U.S. patent number 5,264,338 [Application Number 07/953,782] was granted by the patent office on 1993-11-23 for method for making silver halide emulsion, photosensitive materials using the same, and methods of recording images using the photosensitive materials.
This patent grant is currently assigned to Fuji Photo Film Co., Ltd.. Invention is credited to Shunichi Aida, Shigeharu Urabe.
United States Patent |
5,264,338 |
Urabe , et al. |
November 23, 1993 |
Method for making silver halide emulsion, photosensitive materials
using the same, and methods of recording images using the
photosensitive materials
Abstract
A method of preparing a superfine grain emulsion with a grain
size of 0.05 .mu.m or less is provided, which includes mixing
aqueous solutions of a water-soluble silver salt and a
water-soluble halide with vigorous stirring inside a closed mixing
device furnished with an agitator, where the solutions are fed into
the device simultaneously and continuously, in the presence of at
least one of a high molecular compound and a substance capable of
adsorbing to silver halide, each of which has a physical retardance
value of at least 40 as determined by PAGI method, and immediately
expelling the newly-formed grains from the mixing device. Another
method includes mixing the aqueous solutions in a mixing device as
described above, immediately expelling the newly-formed grains from
the device, and mixing the expelled grains with at least one of the
above-described high molecular compound and substance. The silver
halide photographic materials utilizing the superfine grain
emulsion are suitable for holographic image-recording and
image-recording with electron beam, lasers, and so on.
Inventors: |
Urabe; Shigeharu (Kanagawa,
JP), Aida; Shunichi (Kanagawa, JP) |
Assignee: |
Fuji Photo Film Co., Ltd.
(Kanagawa, JP)
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Family
ID: |
27473710 |
Appl.
No.: |
07/953,782 |
Filed: |
September 30, 1992 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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622682 |
Dec 5, 1990 |
5196300 |
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Foreign Application Priority Data
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Dec 5, 1989 [JP] |
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1-316115 |
Jun 19, 1990 [JP] |
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2-161054 |
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Current U.S.
Class: |
430/568; 430/569;
430/570; 430/583; 430/584; 430/585; 430/593; 430/600; 430/613;
430/627; 430/642 |
Current CPC
Class: |
G03C
5/16 (20130101); G03C 1/015 (20130101) |
Current International
Class: |
G03C
5/16 (20060101); G03C 1/015 (20060101); G03C
001/015 () |
Field of
Search: |
;430/567,569,600,603,568,570,583,584,585,593,613,627,642 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0326852 |
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Aug 1989 |
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EP |
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0374853 |
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Jun 1990 |
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EP |
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Primary Examiner: Baxter; Janet C.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak &
Seas
Parent Case Text
This is a divisional of application No. 07/622,682 filed Dec. 5,
1990, now U.S. Pat. No. 5,196,300.
Claims
What is claimed is:
1. A method of preparing a superfine grain emulsion having an
average grain size of 0.05 .mu.m or less, wherein said method is
continuous and comprises feeding an aqueous solution of a
water-soluble silver salt and an aqueous solution of water-soluble
halide to a first mixing device furnished with an agitator and
having a reaction chamber,
mixing all the solutions in said device to form superfine silver
halide grains, wherein the solutions are present in said device for
a residence time (t) of 20 seconds or less, where the residence
time is expressed by the following equation: ##EQU3## V: the volume
of the reaction chamber in the mixing device (ml) a: the amount of
aqueous silver nitrate solution added (ml/min)
b: the amount of aqueous halide solution added (ml/min)
c: the amount of aqueous protective colloid solution added
(ml/min),
expelling an emulsion containing the formed superfine grains from
said mixing device,
collecting the emulsion expelled from said mixing device,
and then mixing said grains in a second mixing device or a
collection vessel with at least one of a solution of a high
molecular weight compound and a substance capable of adsorbing to
silver halide, each of which has a physical retardance value of at
least 40 as determined by the PAGI method,
wherein the method of preparing a superfine grain emulsion avoids
the occurrence of Ostwald ripening.
2. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein said high molecular weight compound is selected
from the group of a gelatin, a polyvinyl pyrrolidone, a polyvinyl
alcohol, a polymer having a thioether group, a polyvinylimidazole,
a polyethyleneimine, an acetal polymer, an amino polymer, an
acrylamide polymer, a hydroxyquinoline-containing polymer, an
azaindenyl group-containing polymer, a polyalkylene oxide
derivative, a polyvinylamine imide, a polyvinylpyridine, an
imidazolyl group containing vinyl polymer, a triazolyl
group-containing vinyl polymer, and a water-soluble
polyalkyleneaminotriazole.
3. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein said substance capable of adsorbing to silver
halide is a nitrogen-containing heterocyclic compound or a
sensitizing dye.
4. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein said substance capable of adsorbing to silver
halide is a mercapto- or quaternary nitrogen-containing
heterocyclic compound.
5. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein said substance capable of adsorbing to silver
halide is represented by formula (I) or (II): ##STR16## wherein
Z.sub.1 and Z.sub.2, which may be the same or different, each
represents nonmetal atoms completing a 5- or 6-membered
nitrogen-containing hetero ring; Q.sub.1 represents atoms to
complete a 5- or 6-membered nitrogen-containing ketomethine ring;
R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each represents a hydrogen
atom, a lower alkyl group, or an optionally substituted phenyl or
aralkyl group; R.sub.5, R.sub.6 and R.sub.7 each represents an
optionally substituted alkyl or alkenyl group which may contain one
or more oxygen, sulfur or nitrogen atoms in its carbon chain;
l.sub.1 and n.sub.1 each represents 0 or a positive integer of 3 or
less, provided that l.sub.1 +n.sub.1 is 3 or less; j.sub.1, k.sub.1
and m.sub.1 each represents 0 or 1; X.sub.1 .crclbar. represents an
acid anion; and r.sub.1 represents 0 or 1, ##STR17## wherein
Z.sub.11 represents atoms to complete a 5- or 6-membered
nitrogen-containing hetero ring; Q.sub.11 represents atoms to
complete a 5- or 6-membered nitrogen-containing ketomethine ring;
Q.sub.12 represents atoms to complete a 5-or 6-membered ketomethine
ring; R.sub.11 represents a hydrogen atom or an alkyl group;
R.sub.12 represents a hydrogen atom, a phenyl group, or an alkyl
group; R.sub.13 represents an optionally substituted alkyl or
alkenyl group which may contain one or more oxygen, sulfur or
nitrogen atoms in its carbon chain; R.sub.14 and R.sub.15 have the
same meaning as R.sub.13 and additionally represent a hydrogen atom
or a monocyclic aryl group; m.sub.21 represents 0 or a positive
integer of 3 or less; j.sub.21 represents 0 or 1; and n.sub.21
represents 0 or 1.
6. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein said high molecular weight compound is added in an
amount of at least 5 g/mol Ag and said substance capable of
adsorbing to silver halide is added in an amount of at least
10.sup.-5 mol/mol Ag.
7. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein the silver halide emulsion containing the
superfine silver halide grain having the average grain size of 0.05
.mu.m or less is subjected to desalting.
8. The method of preparing a silver halide emulsion as claimed in
claim 1, wherein the silver halide emulsion containing the
superfine silver halide grain having the average grain size of 0.05
or less is subjected to desalting and chemical sensitization.
9. A method as in claim 1, wherein the superfine grains are present
in the second mixing device and are present therein for a time
period of 5 minutes or less.
10. A method as in claim 9, wherein the time period is 1 minute or
less.
Description
FIELD OF THE INVENTION
This invention relates to a method of making a superfine grain
emulsion suitable for silver halide photographic materials, to
silver halide photographic materials obtained utilizing the method
of making a superfine grain emulsion, and to methods of recording
images using the photographic materials.
BACKGROUND OF THE INVENTION
Silver halide photographic emulsions have been used for more than a
century, and silver halide grains have been the subject of zealous
studies for many years. One of the most striking characteristics of
silver halide emulsions is their excellent sharpness.
Factors determining the sharpness of a silver halide photographic
material obtained by coating silver halide emulsions on a support,
and then drying them, are as follows:
(1) Light scattering: Rays of light incident upon a photographic
material are scattered by silver halide grains, resulting in lower
sharpness.
(2) Granularity: An image obtained after development of a
photographic material has a characteristic called granularity,
which can be interpreted as a random-dot model and is basically
attributed to fluctuations in developing individual silver halide
grains.
In T.H. James, The Theory of the Photographic Process, 4th Ed.,
dependence of the scattering factor on particle size for AgBr
grains and AgCl grains in emulsion films are shown in FIG. 20.6 and
FIG. 20.7, respectively (on page 582). As is apparent from those
figures, the light scattering factor shows a clear dependence on
the grain size. More specifically, the light scattering efficiency
factor decreases steeply when the grain size becomes extremely
small (0.1 .mu. or less).
In the above-cited book, the relationship between the grain size
and the granularity are shown in FIG. 21.72, which indicates that
the granularity improves with a decrease in grain size. Therefore,
it is understandable that the reduction of grain size is very
effective for the achievement of high sharpness.
On the other hand, although silver is indispensable for silver
halide emulsions, it should be used in the smallest possible amount
because of its cost and finiteness as a resource. In general, the
transmission density of a developed silver halide emulsion coat is
expressed by the following formula (1) called the Nutting
equation:
where D is the transmission density, n is the number of grains in
an area A, a is the mean projected grain area, and A is the area of
the sampling aperture of the densitometer. When the total volume of
silver grains present in the area A is taken as M, and the size of
an emulsion grain is expressed in terms of a radius (r) of the
sphere equivalent in volume, the following relations hold:
##EQU1##
Substituting the above formulae (3) and (4) in the formula (1)
yields the following equation (5):
D=0.3255 M/(r.multidot.A) (5)
That is, when a particular amount of silver is used, the density
obtained (D) is inversely proportional to the grain radius.
Accordingly, silver halide grains of smaller size are required to
attain a higher transmission density.
In the field of graphic arts, on the other hand, silver halide
light-sensitive materials containing water-soluble rhodium salts
are disclosed, e.g., in JP-A-60-83083 and JP-A-60-162246 (the term
"JP-A" as used herein means an "unexamined published Japanese
patent application") with the intention of obtaining a daylight
photosensitive material of low sensitivity. However, the addition
of rhodium salts in an amount large enough to lower the sensitivity
hinders the contrast-increasing effect of hydrazine compounds,
resulting in a failure to provide the desired image of sufficiently
high contrast.
Because sensitivity is lowered with a decrease in grain size, the
diminution in grain size is more desirable for the lowering of
sensitivity than the addition of water-soluble rhodium salts. Thus,
superfine grains smaller in size are desired.
As for the conventional arts, a "Lippmann" emulsion having an
average grain size of 0.050 .mu.m is disclosed as a silver bromide
fine grain emulsion, e.g., in T.H. James, The Theory of the
Photographic Process, 4th Ed. "Lippmann" emulsions have an average
grain size in the range of 0.05 to 0.1 .mu.m, and they are of great
importance for photographic plates or films having high resolution,
e.g., microphotographs, astrophotographs, masks for production of
electronic integrated circuits, holograms, and so on.
Attempts to change operating conditions during the precipitation of
silver halides have been made for the purpose of obtaining
superfine grains having an average grain size of 0.05 .mu.m or
less. In one method, adding an aqueous silver salt solution and an
aqueous halide solution to an aqueous protective colloid solution
placed in a reaction vessel produces as many grain nuclei as
possible at the time of nucleation in the initial stage of the
addition. However, the continued addition of aqueous silver nitrate
and halide solutions necessarily brings about the growth of the
grain nuclei, so it is impossible in principle to obtain superfine
grains which are extremely small in size (below 0.05 .mu.m).
On the other hand, JP-A-01-183417 (corresponding to U.S. Pat. No.
4,879,208) discloses a method of making silver halide grains, which
comprises placing a mixing device outside a reaction vessel which
contains an aqueous protective colloid solution and is designed to
cause the crystal growth of silver halide grains, feeding aqueous
water-soluble silver salt, water-soluble halide and protective
colloid solutions into the mixing device and mixing these aqueous
solutions therein to form fine grains of silver halide, and
immediately thereafter feeding the fine grains into the reaction
vessel to perform the crystal growth of silver halide grains in the
reaction vessel. In the examples of the above-cited published
patent application, grains expelled from the mixing device have a
size below 0.05 .mu.m. That is to say, if nucleation is carried out
in a mixing device and the grain nuclei are expelled from the
mixing device as soon as they are formed, superfine grains
extremely small in size can be obtained. However, the fine grains
formed in the mixing device have very high solubility because of
their fineness in size, so they cause so-called Ostwald ripening
among themselves to result in an increase of grain size.
In other words, extremely fine grains having been once formed
undergo Ostwald ripening during the washing, redispersion and
redissolution steps, and an increase in grain size thereby
results.
U.S. Pat. Nos. 3,661,592 and 3,704,130 disclose fine grains having
grain sizes smaller than those of Lippmann emulsions (average grain
size: 0.067 .mu.m), which are formed by adding an aqueous
protective colloid solution and a grain-growth inhibitor to a
reaction vessel, and then adding an aqueous silver salt solution
and an aqueous halide solution thereto. In such a method, the
prevention of an increase in grain size is intended by protecting
against grain growth subsequent to nucleation in the reaction
vessel. However, it is impossible to completely prevent grain
growth in the reaction vessel by allowing such adsorbents as
described above to adsorb to individual grain surfaces. The average
grain sizes of the fine grains demonstrated in the examples in the
specifications of the above-cited two patent were within the range
of 0.05 to 0.03 .mu.m with respect to silver bromide.
Accordingly, fine grains smaller in size than Lippmann emulsions
can be obtained, but it is still difficult to obtain superfine
grains even smaller in size. Thus, the existing methods in the art
have not made it feasible to make superfine grain emulsions having
sizes far smaller than those of Lippmann emulsions, although such
emulsions have been strongly desired.
Since fine grain emulsions prepared in accordance with the existing
methods in the art are limited in the lower limit of their grain
sizes, as described above, they are unable to ensure fully
satisfactory properties for silver halide photographic materials
containing them. Consequently, images recorded using those
materials are insufficient in sharpness, which constitutes a very
important factor in image quality, because of light-scattering and
aggravation of granularity which are caused by the insufficiency in
fineness of the silver halide grains.
SUMMARY OF THE INVENTION
Therefore, one object of this invention is to enable the
preparation of a superfine grain emulsion having grains which can
be kept extremely small in size, and to stabilize the preparation
of the superfine grain emulsion.
Another object of this invention is to provide a silver halide
photographic material which contains superfine grain emulsions
having grains which are extremely small in size.
Still another object of this invention is to provide methods of
recording images excellent in sharpness by utilizing silver halide
photographic materials which contain superfine grain emulsions
having extremely small grain sizes.
The preparation of the silver halide emulsion of this invention is
attained by the following Methods (A) and (B) each.
(A) A method of preparing a silver halide emulsion containing
superfine grains, wherein the method comprises feeding an aqueous
solution of a water-soluble silver salt and an aqueous solution of
a water-soluble halide to a mixing device furnished with an
agitator, mixing all the solutions in the device to form superfine
silver halide grains, and expelling the formed superfine grains
from the mixing device immediately thereafter, wherein the method
further comprises forming the superfine grains in the presence of
at least one of a high molecular weight compound and a substance
capable of adsorbing to silver halide, each of which has a physical
retardance value of at least 40, as determined by the PAGI
(Photographic and Gelatin Industries) method, to ensure an average
grain size of 0.05 .mu.m or less.
(B) A method of preparing a superfine grain emulsion having an
average grain size of 0.05 .mu.m or less, wherein the method
comprises feeding an aqueous solution of a water-soluble silver
salt and an aqueous solution of a water-soluble halide to a first
mixing device furnished with an agitator, mixing all the solutions
in the device to form superfine silver halide grains, expelling the
formed superfine grains from the mixing device immediately
thereafter, and then mixing the grains in a second mixing device or
a collection vessel with at least one of a solution of a high
molecular weight compound and a substance capable of adsorbing to
silver halide, each of which has a physical retardance value of at
least 40, as determined by the PAGI method.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of the mixing device of this invention,
including a reaction chamber 1, a rotating shaft 2, agitation
blades 3, a feeding system 4 for an aqueous silver salt solution, a
feeding system 5 for an aqueous halide solution, and an expulsion
outlet 6.
FIG. 2 and FIG. 3 illustrate schematically the methods of this
invention, including mixing devices 11 and 21 for the formation of
superfine grains, aqueous silver nitrate solutions 12 and 22,
aqueous protective colloid solutions 13 and 23, aqueous halide
solutions 14 and 24, a second mixing device 15, an aqueous
protective colloid solution (grain growth retarder) 16, a
collection vessel 25, and an agitator 26.
DETAILED DESCRIPTION OF THE INVENTION
An example of a system which provides the superfine grain formation
of this invention is schematically illustrated in FIG. 1. The
interior of the mixing device is provided with a reaction chamber
1. The reaction chamber 1 is equipped with agitation blades 3
mounted on a rotating shaft 2. Aqueous solutions of a silver salt,
a halide and a protective colloid are introduced into the reaction
chamber from their respective inlets (4, 5 and one which is not
shown in the drawing).
A solution containing superfine grains produced with the aid of
rapid and vigorous mixing achieved by rotating the shaft at a high
speed (500 to 5,000 r.p.m.) is expelled immediately from an outlet
6. The following technical points make it feasible for the
apparatus of this invention to form superfine grains.
(1) The superfine grains are expelled from the mixing device
immediately after having been formed.
In conventional methods, an aqueous silver salt solution and an
aqueous halide solution are added to a reaction vessel in which an
aqueous protective colloid solution is present. It is important for
this reaction system to generate a great number of grain nuclei at
the initial stage of addition, that is, at the time of nucleation.
However, continued addition of the aqueous silver salt (nitrate)
solution and the aqueous halide solution necessarily brings about
the growth of these grain nuclei, so it is impossible to obtain
superfine grains which are extremely small in size.
In this invention, an increase in grain size is prevented by the
instantaneous expulsion of the superfine grains from the mixing
vessel in which they have only just been formed. Specifically, the
residence time (t) of the solutions added to the mixing device is
expressed by the following equation: ##EQU2## V: the volume of the
reaction chamber in the mixing device (ml) a: the amount of aqueous
silver nitrate solution added (ml/min)
b: the amount of aqueous halide solution added (ml/min)
c: the amount of aqueous protective colloid solution added
(ml/min)
In the preparation method of this invention, t is controlled to 10
minutes or less, preferably 5 minutes or less, more preferably 1
minute or less, and most preferably 20 seconds or less. Thus, the
very fine grains formed in the mixing vessel are expelled instantly
from the mixing vessel without the grain size increasing.
(2) Powerful and efficient agitation is effected in the mixing
device.
T.H. James, The Theory of The Photographic Process, p. 93,
describes that "[a]nother type of grain growth that can occur [in
parallel with Ostwald ripening] is coalescence. In coalescence
ripening, an abrupt change in size occurs when pairs or larger
aggregates of crystals are formed by direct contact and welding
together of crystals that were once widely separated. Both Ostwald
and coalescence ripening may occur during precipitation, as well as
after precipitation has stopped. The coalescence ripening described
therein tends to occur in particular in the case where grain sizes
are very small and under insufficient agitation. In an extreme
case, coarse massive grains are generated.
Since, as shown in FIG. 1, a closed mixing device is used in this
invention, the agitation impeller in the reaction chamber can be
rotated at a high speed to effect such powerful and efficient
agitation as not to be realized in conventional open mixing devices
(in an open system, revolution of the agitation impeller at a high
speed is impractical because the centrifugal force generated
thereby scatters the liquid and also causes foaming). Thus,
coalescence ripening can be prevented, resulting in the formation
of superfine grains which are extremely small in size. It is
desirable in this invention that the number of revolutions of the
agitation impeller should range from 500 r.p.m. or more, preferably
1,000 r.p.m. or more.
(3) An aqueous protective colloid solution is injected into the
mixing device.
The above-described coalescence ripening can be prevented to a
considerable extent by the presence of a protective colloid
(peptizer) for silver halide. In this invention, the addition of an
aqueous protective colloid solution to the mixing device is carried
out by any of the following methods.
(a) An aqueous protective colloid solution is injected
independently into a mixing device.
A suitable concentration of the protective colloid is 1 wt % or
higher, preferably 2 wt % or higher, and an appropriate flow rate
thereof is at least 20%, preferably at least 50%, and more
preferably at least 100%, of the total flow rate of the aqueous
silver nitrate and halide solutions.
(b) A protective colloid is incorporated into an aqueous halide
solution.
An appropriate concentration of the protective colloid is 1 wt % or
higher, preferably 2 wt % or higher.
(c) A protective colloid is incorporated into an aqueous silver
nitrate solution.
An appropriate concentration of the protective colloid is 1 wt % or
higher, preferably 2 wt % or higher. When gelatin is used as the
protective colloid, a silver nitrate solution and a gelatin
solution should be mixed just before their use, since gelatin
silver is formed between silver ions and gelatin molecules and
converted to colloidal silver by undergoing photolysis and/or
pyrolysis.
The above-described methods (a) to (c) may be employed
independently or in any combination thereof.
A suitable reaction temperature in the mixing device is below
50.degree. C., preferably below 40.degree. C., and more preferably
below 30.degree. C. When reaction temperatures are below 35.degree.
C., ordinary gelatins are subject to coagulation, so it is
desirable that low molecular weight gelatins (weight average
molecular weight: less than 30,000) should be used.
The grain sizes obtained in accordance with the above-described
techniques (1) to (3) can be confirmed by putting the grains on
meshes, and observing them under a transmission electron
microscope. A suitable magnification for the observation is from
20,000 to 40,000. The size of the fine grains of this invention is
below 0.05 .mu.m, preferably below 0.03 .mu.m, and more preferably
below 0.02.
The fine grains formed in the mixing device have very high
solubility because of their fineness in size and, therefore, cause
so-called Ostwald ripening among themselves after their expulsion
from the mixing device, resulting in an increase in grain size.
That is, according to the above-described methods alone, the
superfine grains experience Ostwald ripening during the subsequent
processing steps, which include washing, redispersion,
redissolution, chemical sensitization and storage, and an increase
in grain size is caused thereby.
In this invention, the above-described problem is resolved by each
of the following methods (A) and (B).
(A) In a method of forming superfine grains by feeding an aqueous
solution of a water-soluble silver salt, an aqueous solution of a
water-soluble halide and an aqueous protective colloid solution to
a mixing device furnished with an agitator, mixing the solutions in
the device to form superfine silver halide grains, and expelling
the formed superfine grains from the mixing device immediately
thereafter, the formation of the superfine grains is carried out in
the presence of at least one of a high molecular weight compound
and a substance capable of adsorbing to silver halide, each of
which has a physical retardance value of at least 40, as determined
by the PAGI method.
(B) A superfine grain emulsion is prepared by feeding an aqueous
solution of a water-soluble silver salt, an aqueous solution of a
water-soluble halide and an aqueous protective colloid solution to
a mixing device furnished with an agitator, mixing the solutions in
the device to form superfine silver halide grains, expelling the
formed superfine grains from the mixing device immediately
thereafter, and then mixing the grains with a solution of at least
one of a high molecular weight compound and a substance capable of
adsorbing to silver halide, each of which has a physical retardance
value of at least 40, as determined by the PAGI method.
In this invention, the physical retardance is determined by the
PAGI (Photographic and Gelatin Industries) method. This method is
described in detail below.
1. Outline of Method
Silver chloride grains are formed in a gelatin solution and
subjected to physical ripening. The resulting emulsion is examined
for turbidity.
2. Instrument and Device
(1) turbidimeter and spectrophotometer
(2) thermostat (60.0.+-.0.5.degree. C.)
3. Preparation of Test Solution
______________________________________ Solution A: Sodium chloride
17.6 g M/2 Sulfuric acid 100 ml Water to make 1,000 ml Solution B:
Silver nitrate 17.0 g Water to make 1,000 ml
______________________________________
The reagents used are all special grade or equivalent thereto.
(1) 30 g of a sample gelatin is dissolved in 300 ml of water. A 100
ml portion of the resulting solution is admixed with a 20 ml
portion of the solution A and heated at 60.0.+-.0.5.degree. C.
(2) A 20 ml portion of the solution B (at 60.degree. C.) is added
over a 2- to 3-second period to the above-described mixture with
stirring.
(3) The thus prepared silver chloride emulsion is physically
ripened at 60.0.+-.0.5.degree. C. for 20 minutes. During the
ripening, the emulsion is stirred by moving a glass rod around 20
times in the period after a 10-minute lapse after the beginning of
ripening and just before the conclusion of the ripening.
(4) A 5 ml portion of the thus ripened emulsion is pipetted and
admixed with 30 ml of water (room temperature) with stirring to
prepare a test solution.
4. Measurement
(1) Transmittance at 600 nm is measured with a
spectrophotometer.
(2) A cell 10 mm in thickness is used.
According to this invention, the superfine grains are either formed
in the presence of or mixed with at least one of a high molecular
weight compound (a protective colloid polymer) and a substance
capable of absorbing to silver halide (a grain-growth retarder),
each of which has a physical retardance value of at least 40, as
determined by the PAGI method set forth above. The protective
colloid polymers and grain-growth retarders are described in detail
below.
1. Protective Colloid Polymers
Protective colloid polymers which can be used are roughly divided
into main three groups: gelatins, other natural polymers, and
synthetic polymers. The physical retardance of gelatins is
determined by the PAGI method described above. Natural polymers,
other than gelatins, and synthetic polymers can be also examined
for physical retardance in accordance with the same PAGI method,
except that the polymers are substituted for the gelatins in the
same amount.
A requirement for the protective colloid polymers to be used in
this invention is that their physical retardance be at least 40.
Specific examples of polymers which satisfy said the requirement
are given below.
(1) Gelatin retarders having high physical retardance (gelatins
having high adenine and guanidine contents).
(2) Polyvinyl pyrrolidones; vinyl pyrrolidone homopolymer and
acrolein-vinyl pyrrolidone copolymers disclosed in French Patent
2,031,396.
(3) Polyvinyl alcohols; vinyl alcohol homopolymer, organic acid
monoesters of polyvinyl alcohols disclosed in U.S. Pat. No.
3,000,741, maleic acid esters of polyvinyl alcohols disclosed in
U.S. Pat. No. 3,236,653, and vinyl alcohol-vinyl pyrrolidone
copolymers disclosed in U.S. Pat. No. 3,479,189.
(4) Polymers having thioether groups; thioether group-containing
polymers disclosed in U.S. Pat. Nos. 3,615,624, 3,860,428 and
3,706,564.
(5) Polyvinylimidazoles; vinyl imidazole homopolymer, vinyl
imidazole-vinyl amide copolymers, and acrylamide-acrylic acid-vinyl
imidazole terpolymers disclosed in JP-B-43-7561 (the term "JP-B" as
used herein means an "examined Japanese patent publication"), and
German Patents 2,012,095 and 2,012,970.
(6) Polyethyleneimines.
(7) Acetal polymers; water-soluble polyvinyl acetals disclosed in
U.S. Pat. No. 2,358,836, carboxyl group-containing polyvinyl
acetals disclosed in U.S. Pat. No. 3,003,879, and polymers
disclosed in British Patent 771,155.
(8) Amino polymers; amino polymers disclosed in U.S. Pat. Nos.
3,345,346, 3,706,504 and 4,350,759, and West German Patent
2,138,872, quaternary amine-containing polymers disclosed in
British Patent 1,413,125 and U.S. Pat. No. 3,425,836, polymers
containing both amino and carboxyl groups disclosed in U.S. Pat.
No. 3,511,818, and polymers disclosed in U.S. Pat. No.
3,832,185.
(9) Acrylamide polymers; acrylamide homopolymer,
acrylamide-imidated acrylamide copolymers disclosed in U.S. Pat.
No. 2,541,474, acrylamide-methacrylamide copolymers disclosed in
West German Patent 1,202,132, partially aminated acrylamide
polymers disclosed in U.S. Pat. No. 3,284,207, and substituted
acrylamide polymers disclosed in JP-B-45-14031, U.S. Pat. Nos.
3,713,834 and 3,746,548, and British Patent 788,343.
(10) Hydroxyquinoline-containing polymers;
hydroxyquinoline-containing polymers disclosed in U.S. Pat. Nos.
4,030,929 and 4,152,161.
(11) Others; azaindenyl group-containing polymers disclosed in
JP-A-59-8604, polyalkylene oxide derivatives disclosed in U.S. Pat.
No. 2,976,150, polyvinylamine imides disclosed in U.S. Pat. No.
4,022,623, polymers disclosed in U.S. Pat. Nos. 4,294,920 and
4,089,688, polyvinylpyridines disclosed in U.S. Pat. No. 2,484,456,
imidazolyl group-containing vinyl polymers disclosed in U.S. Pat.
No. 3,520,857, triazolyl group-containing vinyl polymers disclosed
in JP-B-60-658, and water-soluble polyalkyleneaminotriazoles
described in Zeischrift Wissenschaftrilich Photographic, Vol. 45,
p. 43 (1950).
Secondly, substances capable of retarding the growth of superfine
grains through the adsorption to silver halides (which are called
"grain-growth retarders", hereinafter) are described below.
2. Grain-Growth Retarders
In the determination of the physical retardance according to the
PAGI method, 30 g of an inert gelatin having a physical retardance
ranging from 10 to 15 is used as a protective colloid, and
2.times.10.sup.-5 mole of an adsorbent is added to the gelatin
solution. Then, the resulting gelatin solution is examined for
physical retardance. Adsorbents which realize a physical retardance
of at least 40 under the above-described condition are those which
satisfy the objects of this invention.
The adsorbents applicable to this invention are illustrated more
specifically below.
2-1 Nitrogen-containing heterocyclic compounds which have one or
more mercapto groups to form mercaptosilver in combination with a
silver ion:
Specific examples thereof are illustrated below. ##STR1##
2-2 Nitrogen-containing heterocyclic compounds which can form
iminosilver in combination with silver ion:
Specific examples thereof are illustrated below. ##STR2## 2-3
Quaternary nitrogen-containing heterocyclic compounds:
Specific examples thereof are illustrated below. ##STR3##
2-4 Sensitizing dyes:
In this invention, sensitizing dyes can be used because they have a
grain-growth retarding effect. Moreover, it becomes necessary to
spectrally sensitize the superfine grain emulsions of this
invention, if needed by the end-use purpose, e.g., in order to
impart thereto spectral sensitivities suitable for spectral
characteristics of light to be used for recording images. In such a
case, it is quite reasonable to use sensitizing dyes having both
grain-growth retardation and spectral sensitization functions.
The amount of the sensitizing dye used in the invention changes by
the size of the superfine grain silver halide emulsion, the
adsorption of the sensitizing dye., and the solubility of the
sensitizing dye to a solvent. Thus it is difficult to define the
amount of the sensitizing dye. In general, however/ the amount of
the sensitizing dye is about 1.times.10.sup.-5 mol to 1 mol,
preferably about 3.times.10.sup.-3 to 5.times.10.sup.-1 mol per mol
of silver halide. Depending on the type of the protective colloid
and the grain growth retarder, the protective colloid and the grain
growth retarder, the sensitizing dye may be used in a smaller
amount than defined above.
Sensitizing dyes which can be used in this invention include
cyanine dyes, merocyanine dyes, or complex cyanine dyes. Preferred
dyes are represented by the following formula (I) or (II):
##STR4##
In the foregoing formula, Z.sub.1 and Z.sub.2 may be the same or
different, and each represents nonmetal atoms completing a 5- or
6-membered nitrogen-containing hetero ring, with specific examples
including thiazoline, thiazole, benzothiazole, naphthothiazole,
selenazoline, selenazole, benzoselenazole, naphthoselenazole,
oxazole, benzoxazole, naphthoxazole, benzimidazole,
naphthimidazole, pyridine, quinoline, indolenine,
imidazo[4,5-b]quinoxaline and benzotellurazole rings. These hetero
rings may have one or more substituent groups. Suitable examples of
such substituent groups include lower alkyl groups (preferably
containing 1 to 6 carbon atoms, which may be further substituted by
a hydroxyl group, a halogen atom, phenyl group, a substituted
phenyl group, a carboxyl group, an alkoxy carbonyl group, an alkoxy
group, or some other substituent), lower alkoxy groups (preferably
containing 1 to 6 carbon atoms), acylamino groups (preferably
containing less than 8 carbon atoms) a C.sub.6-12 monocyclic aryl
group, carboxyl group, lower alkoxycarbonyl groups (preferably
containing less than 6 carbon atoms), a hydroxyl group, cyano
group, halogen atoms, and so on.
In addition, when the hetero ring represented by Z.sub.1 or Z.sub.2
contains the other nitrogen atom which can have a substituent
group, e.g., benzimidazole, naphthoimidazole,
imidazo-[4,5-b]quinoxaline or the like, that nitrogen atom may have
a substituent group such as an alkyl or alkenyl group containing 1
to 6 carbon atoms (which may be further substituted by a hydroxyl
group, an alkoxy group, a halogen atom, a phenyl group, an
alkoxycarbonyl group or some other substituent).
Q.sub.1 represents atoms to complete a 5- or 6-membered
nitrogen-containing ketomethine ring, such as thiazolidine-4-one,
selenazolidine-4-one, oxazolidine-4-one, imidazolidine-4-one, or
the like.
R.sub.1, R.sub.2, R.sub.3 and R.sub.4 each represents a hydrogen
atom, a lower alkyl group (preferably containing 1 to 4 carbon
atoms), or an optionally substituted phenyl or C.sub.6-12 aralkyl
group. In addition, when l.sub.1 represents 2 or 3, or when n.sub.1
represents 2 or 3, a 5- or 6-membered ring which may contain
oxygen, sulfur, nitrogen and/or other hetero atoms can be formed by
combining R.sub.1 with another R.sub.1, R.sub.2 with another
R.sub.2, R.sub.3 with another R.sub.3, or R.sub.4 with another
R.sub.4.
R.sub.5, R.sub.6 and R.sub.7 each represents an optionally
substituted alkyl or alkenyl group which contains 1 to 10 carbon
atoms, and may contain one or more oxygen, sulfur or nitrogen atoms
in its carbon chain. Suitable examples of substituent groups which
they may have include a sulfo group, a carboxyl group, a hydroxyl
group, a halogen atom, an alkoxycarbonyl group, a carbamoyl group,
a phenyl group, a substituted phenyl group, and so on.
In formula (I), l.sub.1 and n.sub.1 each represents 0 or a positive
integer of 3 or less, provided that l.sub.1 +n.sub.1 is 3 or less.
When l.sub.1 is 1, 2 or 3, R.sub.5 may combine with R.sub.1 to form
a 5- or 6-membered ring.
In addition, j.sub.1, k.sub.1 and m.sub.1 each represents 0 or
1.
X.sub.1.sup.- represents an acid anion, and r.sub.1 represents 0 or
1.
It is to be desired in the formula (I) that at least one among the
substituents R.sub.5, R.sub.6 and R.sub.7 should be a group
containing a sulfo or carboxyl group. ##STR5##
In the above formula (II) , Z.sub.11 represents atoms to complete a
5- or 6-membered nitrogen-containing hetero ring. For instance, it
completes a heterocyclic nucleus to be used for forming one of
conventional cyanine dyes, with specific examples including
thiazoline, thiazole, benzothiazole, naphthothiazole, selenazoline,
selenazole, benzoselenazole, naphthoselenazole, oxazole,
benzoxazolene, naphthoxazole, benzimidazole, naphthimidazole,
pyridine, quinoline, pyrrolidine, indolenine,
imidazo[4,5-b]quinoxaline, tetrazole and like nuclei. These
heterocyclic nuclei each may be substituted, e.g., by a lower alkyl
group (preferably containing 1 to 10 carbon atoms, which may be
further substituted by a hydroxyl group, a halogen atom, phenyl
group, a substituted phenyl group, carboxyl group, an
alkoxycarbonyl group, an alkoxy group, or some other substituent),
a lower alkoxy group (preferably containing 1 to 7 carbon atoms),
an acylamino group (preferably containing 1 to 8 carbon atoms) a
C.sub.6-12 monocyclic aryl group, a C.sub.6-12 monocyclic aryloxy
group, a carboxyl group, a lower alkoxycarbonyl group (preferably
containing 2 to 7 carbon atoms), a hydroxy group, a cyano group, a
halogen atom, or some other substituent).
Q.sub.11 represents atoms to complete a 5- or 6-membered
nitrogen-containing ketomethine ring, such as thiazolidine-4-one,
selenazolidine-4-one, oxazolidine-4-one, imidazolidine-4-one, or
the like.
Q.sub.12 represents atoms to complete a 5- or -6-membered
ketomethylene ring. Examples of such atoms include those completing
heterocyclic nuclei to constitute conventional merocyanine dyes,
such as rhodanine, 2-thiohydantoin, 2-selenathiohydantoin,
2-thioxazolidine-2,4-dione, 2-selenaoxazolidine-2,4-dione,
2-thioselenazolidine-2,4-dione, 2-selenathiazoline-2,4-dione,
2-selenazolidine-2,4-dione, and the like.
When the atoms completing the heterocyclic ring represented by
Z.sub.11, Q.sub.11 or Q.sub.12 contain not less than two nitrogen
atoms as their constituents, as in the case of benzimidazole,
thiohydantoin or a like ring, one or more nitrogen atoms other than
the one which combines with R.sub.13, R.sub.14 or R.sub.15,
respectively, may be substituted, e.g., by an alkyl or alkenyl
group containing 1 to 8 carbon atoms, in which a carbon atom in its
alkyl chain may be replaced by an oxygen, sulfur of nitrogen atom,
or may have a substituent group, or an optionally substituted
monocyclic aryl group.
R.sub.11 represents a hydrogen atom or an alkyl group containing 1
to 4 carbon atoms, and R.sub.12 represents a hydrogen atom, or a
phenyl group (which may be substituted, e.g., by an alkyl or alkoxy
group containing 1 to 4 carbon atoms, a halogen atom, a carboxyl
group, a hydroxyl group, or some other substituent), or a C.sub.1-8
alkyl group (which may be substituted, e.g., by a hydroxyl group, a
carboxyl group, an alkoxy group, a halogen atom, or some other
substituent). When m represents 2 or 3, R.sub.12 may combine with
another R.sub.12 to complete a 5- or 6-membered ring in which an
oxygen, sulfur or nitrogen atom may be contained.
R.sub.13 represents an optionally substituted alkyl or alkenyl
group which contains 1 to 10 carbon atoms, and may contain one or
more oxygen, sulfur or nitrogen atoms in its carbon chain. Suitable
examples of substituent groups which they may have include a sulfo
group, a carboxyl group, a hydroxyl group, a halogen atom, an
alkoxycarbonyl group, a carbamoyl group, a phenyl group, a
substituted phenyl group, and a monocyclic saturated heterocyclic
group.
R.sub.14 and R.sub.15 have the same meaning as R.sub.13, and
additionally may represent a hydrogen atom or a C.sub.6-12
monocyclic aryl group (which may be substituted, e.g., by a sulfo
group, a carboxyl group, a halogen atom, an alkyl, acylamino or
alkoxy group containing 1 to 5 carbon atoms, or some other
substituent).
In formula (II), m.sub.21 represents 0 or a positive integer of 3
or less, j.sub.21 represents 0 or 1, and n.sub.21 represents 0 or
1. When m.sub.21 is 1, 2 or 3, R.sub.11 may combine with R.sub.13
to form a 5- or 6-membered ring.
It is to be desired in the formula (II) that at least one among the
substituents R.sub.13, R.sub.14 and R.sub.15 should be a group
containing a sulfo or carboxyl group.
Specific examples of compounds represented by the formula (I) are
illustrated below. ##STR6##
Specific examples of compounds represented by the formula (II) are
illustrated below. ##STR7##
The superfine grain emulsion prepared in accordance with this
invention may have any halide composition, including iodide,
iodobromide, bromide, chlorobromide, chloride, chloroiodide and
chloroiodobromide.
As for the particular apparatus to be used in forming superfine
grains in accordance with this invention, those disclosed in the
patents specified below can be employed.
JP-A-164719, JP-A-2-163735, JP-A-2-172815 and JP-A-2-167819 are
cited with respect to the formation of superfine grains,
JP-A-2-167817 with respect to the structure of a mixing device, and
JP-A-2-172816 with respect to the desalting and the concentration
of a superfine grain emulsion by means of a functional film.
Specific methods to be employed in adding the high molecular
compounds (protective colloid polymers) and the grain-growth
retarders of this invention, each of which has a physical
retardance value of at least 40, as determined by the PAGI method,
are described below. Method A:
The protective colloid polymer of this invention can be used in
three ways. That is, one way involves the independent injection of
an aqueous protective colloid polymer solution into a mixing
device, a second way involves the addition of the protective
colloid polymer to an aqueous halide solution, and a third way
involves the addition of the protective colloid polymer to an
aqueous silver salt solution. These three ways may be used
independently or combined in any manner. Of course, the three may
be carried out at the same time. Also, the protective colloid
polymers of this invention can be used in combination with
gelatins.
The grain-growth retarders of this invention are used in
combination with the protective colloid polymer or gelatins
(including low molecular weight ones) since they themselves do not
function as protective colloids. Specifically, the grain-growth
retarders can be used two ways. One way involves the addition of
the grain-growth retarder to an aqueous solution of a protective
colloid polymer or gelatin, and the other way involves the addition
of the grain-growth retarder to an aqueous halide solution. These
two ways may be carried out at the same time. Method B:
In Method B, superfine grains are expelled from the mixing vessel
as soon as they are formed, and the expelled emulsion is introduced
immediately into a second mixing device. Simultaneously with the
introduction of this emulsion, an aqueous solution of the
protective colloid polymer or the grain-growth retarder of this
invention is injected into the second mixing device, and mixed
therein. This system is schematically shown in FIG. 2. A mixing
device such as that shown in FIG. 1 is used as the second mixing
device. The time taken to introduce the emulsion expelled from the
mixing device used for grain formation into the second mixing
device is controlled to, 10 minutes or less, preferably 5 minutes
or less, more preferably 1 minute or less, and most preferably 30
seconds or less. The residence time of the emulsion in the second
mixing device is controlled to 5 minutes or less, preferably 1
minute or less, and more preferably 30 seconds or less.
Instead of using the second mixing device, a collection vessel
having an agitator, such as that shown in FIG. 3, can be used, and
the superfine grain emulsion expelled from the mixing device and
the protective colloid polymer and/or the grain-growth retarder of
this invention are mixed therein.
The time taken to introduce the emulsion expelled from the mixing
device used for the formation of superfine grains into the
collection vessel is controlled to 10 minutes or less, preferably 5
minutes or less, more preferably 1 minute or less, and most
preferably 30 seconds or less.
In both Methods A and B of this invention, the protective colloid
polymer and the grain-growth retarder are used in the following
amounts, respectively.
Protective colloid polymer:
5 g/mol Ag or more, preferably 10 g/mol Ag or
more, and more preferably 20 g/mol Ag or more.
Grain-growth retarder:
10.sup.-5 mol/mol Ag or more, preferably 10.sup.-4 mol/mol
Ag or more, and more preferably 10.sup.-3 mol/mol Ag
or more.
Emulsions relating to this invention can be spectrally
sensitized.
In general, methine dyes are used as spectral sensitizing dyes in
this invention. They include cyanine dyes, merocyanine dyes,
complex cyanine dyes, complex merocyanine dyes, holopolar cyanine
dyes, hemicyanine dyes, styryl dyes, and hemioxonol dyes. Any
nuclei usually present in cyanine dyes can be the basic
heterocyclic nuclei of the above-cited dyes. More specifically,
basic heterocyclic nuclei include pyrroline, oxazoline, thiazoline,
pyrrole, oxazole, thiazole, selenazole, imidazole, tetrazole,
pyridine and like nuclei; nuclei formed by fusing together one of
the above-cited nuclei and an alicyclic hydrocarbon ring; and
nuclei formed by fusing together one of the above-cited nuclei and
an aromatic hydrocarbon ring. Specific examples of these nuclei
include indolenine, benzindolenine, indole, benzoxazole,
naphthoxazole, benzothiazole, naphthothiazole, benzoselenazole,
benzimidazole, quinoline and like nuclei. Each of these nuclei may
have a substituent group on a carbon atom.
The merocyanine and complex merocyanine dyes can contain 5- or
6-membered heterocyclic nuclei, such as pyrazoline-5-one,
thiohydantoin, 2-thioxazolidine-2,-4-dione, thiazolidine-2,4-dione,
rhodanine, thiobarbituric acid and like nuclei, as ketomethylene
structure-containing nuclei.
Sensitizing dyes are added to emulsions before, during, or after
chemical ripening. It is most desirable that sensitizing dyes
should be added to the silver halide grains of this invention
before or during the chemical ripening (e.g., at the time of grain
formation or physical ripening).
The superfine grain silver halide emulsion of this invention is
usually subjected to desalting (including flocculation step,
redispersion step, etc).
The superfine grain silver halide emulsion of this invention is
usually chemically sensitized.
More specifically, sulfur sensitization using active gelatin or
compounds containing sulfur capable of reacting with silver ions
(e.g., thiosulfates, thioureas, mercapto compounds, and
rhodanines), reduction sensitization using reducing materials (e.g.
, stannous salts, amines, hydrazine derivatives, formamidine
sulfinic acid, and silane compounds), sensitization with noble
metal compounds (e.g., gold complexes, and complexes of Group VIII
metals, such as Pt, Ir, Pd, etc.), and so on can be employed
individually or as a combination thereof.
The photographic emulsions to be used in this invention can contain
a wide variety of compounds for the purposes of preventing fog or
stabilizing photographic functions during production, storage, or
photographic processing. Specifically, azoles such as
benzothiazolium salts, nitroindazoles, triazoles, benzotriazoles,
and benzimidazoles (especially nitro- or halogen-substituted ones);
heterocyclic mercapto compounds, such as mercaptothiazoles,
mercaptobenzothiazoles, mercaptobenzimidazoles,
mercaptothiadiazoles, mercaptotetrazoles (especially
1-phenyl-5-mercaptotetrazole) and mercaptopyrimidines; the same
heterocyclic mercapto compounds as cited above except for
containing one or more water-soluble groups, such as a carboxyl
group, sulfo group, etc. thioketo compounds, such as
oxazolinethione; azaindenes, such as tetraazaindenes (especially
4-hydroxy-substituted (1,3,3a,7)tetraazaindene);
benzenethiosulfonic acids; benzenesulfonic acid; and other
compounds which have so far been known as antifoggants or
stabilizers can be added to the photographic emulsions.
These antifoggants and stabilizers, though usually added after the
chemical sensitization, are preferably added in the course of the
chemical ripening, or before the start of the chemical
ripening.
The emulsions of this invention can be applied to a photographic
light-sensitive material having any layer structure (monolayer or
multilayer).
That is, the second and third objects of this invention can be
attained by the embodiments described below.
(a) A silver halide photographic material having at least one
emulsion layer on a support, with the emulsion layer containing the
superfine grain emulsion prepared in accordance with the foregoing
method (A) or (B) as at least one constituent light-sensitive
silver halide emulsion thereof.
(b) A method of recording holographic images by subjecting the
silver halide photographic material of the above-described
embodiment (a) to the exposure for holographic image-recording.
(c) A method of recording electron-beam images by irradiating the
silver halide photographic material of the above-described
embodiment (a) with electron beams.
(d) A method of recording electron-beam images, in which the silver
halide photographic material of the above-described embodiment (a)
is provided additionally with a conductive layer, and the resulting
material is irradiated imagewise with electron beams.
(e) A method of recording high-density images, in which the silver
halide photographic material of the above-described embodiment (a)
is subjected to scanning exposure to record high-density images
therein.
As is apparent from the descriptions concerning the background of
this invention, the silver halide photographic material according
to the foregoing embodiment (a) has excellent sharpness. The
excellent sharpness inherent in the silver halide photographic
material of this invention is a property which is independent of
exposure method. However, in order for an improvement in sharpness
to acquire a practical significance with respect to the recorded
images, the recording method itself should have high resolution.
Suitable examples of exposure methods for high resolution recording
of images include those using light sources of short in wavelength
or rich in ultraviolet rays such as mercury lamp (wherein the use
of X-rays may be used as light (electromagnetic waves) of shorter
wavelengths), those using light sources of strong coherency (lasers
or the like), and exposure with electron beams. Of these methods,
the image recording methods according to the above-described
embodiments (b), (c), (d), and (e) are preferred in particular.
In the recording of holographic images, an interference fringe of
light which is generated by the interference of light from an
object (object wave) with the reference wave is recorded on the
surface of a photographic light-sensitive material, and a
stereoimage corresponding to the original object wave is reproduced
from the recorded interference fringe at the time of
image-reproduction. Consequently, the quality of the holographic
image depends largely upon how faithfully the photographic
light-sensitive material can record the interference fringe of
light which is generated in the above-described process. Therefore,
an expectation that high sharpness realized with the silver halide
photographic material of this invention will be very useful for the
recording of holographic images is achieved by the foregoing
embodiment (b).
In carrying out the recording of holographic images, one can refer
to various books which have been published. For example, one can
refer to Holography no Kiso to Jikken (which means "Fundamentals
and Experiments of Holography"), written by Norimitsu Hirai,
compiled by Akira Matsushita, published by Kyoritsu Shuppan in
1979, Holographic Recording Materials, edited by H.M. Smith,
published by Springer Verlag in 1977, and so on.
The resolving power in recording images with a single light source
can be heightened, as described above, by using light of short
wavelengths, light of high coherency, or like means. However,
resolution finer than the wavelengths of light used cannot be
expected so long as light is used, except for special cases
utilizing the interference of light, as represented by the
holographic image-recording. In addition, various restrictions are
placed on light sources for practical use. Consequently, the
resolving power realizable in the image-recording with light has
its limit in itself. For the purpose of getting over this limit to
obtain still higher resolving power, recording images by means of
electron beams has been tried. Since the wavelength of electron
beams becomes shorter as the acceleration voltage is set higher,
the resolving power in the image-recording with electron beams can
be heightened with ease, compared with the case of the
image-recording with light. However, the use of conventional silver
halide photographic materials as a recording medium in the
electron-beam recording is apt to be hampered by their own
resolving power. Therefore, an expectation that high sharpness
realized with the silver halide photographic material of this
invention will be very useful for the image-recording with electron
beams is achieved the foregoing embodiment (c).
In performing the exposure to electron beams for the purpose of
heightening the resolving power, one can refer to the descriptions,
e.g., in Electron-Ion Beams Handbook, 2nd Ed., edited by Nippon
Gakujutsu Shinkokai (Committee 132), published by Nippon Kogyo
Shinbunsha in 1987. As for the application and the development of
this art, though there are few descriptions of the case in which
silver halide photographic materials are utilized, one can refer to
Electron-Beam, X-ray, and Ion-beam Technology: Submicrometer
Lithographies VIII, edited by A.W. Yanof, published by SPIE- The
International Society for Optical Engineering in 1989, and so on.
For the details of the exposure of silver halide photographic
materials to electron beams, one can refer to T.H. James, The
Theory of the Photographic Process, 4th ed., Macmillan Publishing
(1977), C.I. Coleman, J. Phot. Sci., Vol. 23, P. 50 (1975), and so
on.
According to those descriptions, incident electron beams which
permeate into a silver halide photographic material are spread out
by scattering due to the presence binder particles and silver
halide grains in photographic emulsion layers. Although this
phenomenon can be suppressed by reducing the thickness of each
emulsion layer to control the drop in resolving power, the
reduction in thickness results in a lowering of the proportion of
effectively used electrons, that is, a lowering of sensitivity. The
degree of spread of electron beams in emulsion layers and the
sensitivity of silver halide grains depend largely upon the energy
of incident electron beams. Taking into the account the
above-described situation in designing silver halide photographic
materials, those which satisfy the purpose can be prepared.
On the other hand, though it somewhat differs in standpoint from
the above description, the exposure of silver halide photographic
materials to electron beams is an effective means in the case where
the primary image information is an electric one, such as video
signals. For details of the application described above, one can
refer to P.F. Grosso, J.P. Whitley and V.P. Morgan, "Electron beam
recording for high quality hard copy output" in Hard Copy Output,
edited by L. Beiser, published by SPIE- The International Society
for Optical Engineering in 1989, and so on.
In image-recording with electron beams, electron beams permeating
into a recording film in the course of recording lose their energy
through the formation of a latent image in the silver halide grains
present inside the film and the diffusion throughout the film, and
thereby they are converted to low energy electrons. These electrons
are gradually accumulated as charges on the film surface and cause
the deflection of the succeeding electron beams which are incident
on that surface in the recording process, resulting in distortion
of the recorded image.
For the purpose of preventing this phenomenon from occurring, and
thereby protecting the recorded image against distortion,
inventions have been made which involve imparting conductivity to
silver halide photographic materials for electron-beam recording to
prevent the accumulation of charges. In recording electron-beam
images using the silver halide photographic materials in accordance
with the embodiment (a) of this invention, it is desirable to
employ those inventions in combination. Since the silver halide
photographic materials of this invention are relatively low in
sensitivity because the silver halide grains therein are fine in
size, much exposure tends to be required for effecting the
recording of images with electron beams. Such being the case, it
has turned out that an especially desirable effect can be produced
by providing the photographic materials of this invention with a
conductive layer. Thus, the foregoing embodiment (d) of this
invention has been developed. As for a particular way to make a
conductive layer, one can refer to the descriptions in U.S. Pat.
No. 3,336,596, British Patent 1,340,403, JP-B-49-24282,
JP-A-64-70742 and references cited therein.
The relatively low sensitivity inherent in the silver halide
photographic material of this invention due to the fineness of its
silver halide grains in size, as described hereinbefore, implies
that a relatively large quantity of exposure is required for
recording images with light. In recording images on the order of
several microns to submicrons in high density, not only pattern
exposure through a mask but also scanning exposure which enables
precise control of the image-recording is carried out
advantageously. Though both exposure methods are applicable to the
silver halide photographic materials of this invention, it has been
found by the inventors of this invention that the latter scanning
exposure is preferred in particular when the silver halide
photographic materials of this invention are employed.
The reasons for the preference of the scanning exposure are as
follows. The recording of images through scanning exposure is
carried out by making a fine spot-form luminous flux move on a
recording medium, so the residence time of the luminous flux at
each exposed spot is short. In addition, an exposure greater than
some definite value is reuired for sensitizing silver halide
grains. In the scanning exposure, therefore, the illuminance at the
exposed spot is generally set to a high intensity in order to
ensure the necessary exposure to the recording medium in a short
time. As a result of our examinations, it has been found that in
the high-intensity short-time exposure as described above,
sensitivity drop caused by the use of the silver halide
photographic materials of this invention is relatively small. It
can be regarded as a cause of the small drop in sensitivity that
though the sensitivity of the silver halide grains of this
invention is low because of their small size, the smallness in
grain size lessens the probability of latent-image dispersion,
which has a tendency to occur in high intensity exposure. Moreover,
a low probability of light-scattering, which is a characteristic of
the silver halide photographic materials of this invention, as
described in the foregoing "Background of the Invention", makes it
hard for spots actually recorded on the recording medium to be
extended in size through the irradiation inside the recording
medium (that is, changes in scattering behavior of light which is
caused by the variation in incident angle of the recording spot on
the recording medium), and like ones. Therefore, this
characteristic also is useful in particular for high density
recording by means of scanning exposure. Thus, the foregoing
embodiment (e) of this invention has been developed.
Since high resolving power is an important characteristic of the
silver halide photographic materials of this invention, the
preparation and handling of the photographic materials must be
carried out with caution so as not to adversely affect that
characteristic. For instance, caution must be employed such that
factors constituting obstacles to the writing and reading of image
information, such as foreign matter like dust, scratches on the
surface and so on, are removed in every way, or the writing and
reading of image information is carried out in liquid having a
refractive index close to that of the photographic material in
order to exclude influences of external disturbance, e.g., dust,
reflection, etc. Moreover, as for the method of preventing the
image information from being altered in the course of development
processing, experimental arts cultivated for the purpose of
analyzing tracks of elementary particles, such as nuclear
emulsions, serve as especially influential references. An example
of such a reference is the above-cited paper, C.I. Coleman, J.
Photo. Sci., Vol. 23, p. 50 (1975).
On the other hand, in the case where flatness of the recording
medium constitutes an important factor in recording and reproducing
images, as in holographic image recording, caution as to the use of
a support having only slight distortion, such as glass, should be
taken, if needed.
A silver halide multilayer color photographic material utilizing
the emulsion prepared in accordance with this invention has a
multilayer structure in which three kinds of emulsions for
recording blue, green and red rays separately are consecutively
layered, wherein each layer contains a binder and silver halide
grains. Each emulsion layer has at least two constituent layers (a
high sensitivity layer and a low sensitive layer).
The silver halide emulsions of this invention can be applied not
only color photographic materials, as described above, but also to
other photographic materials, irrespective of the number of
emulsion layers they have, with specific examples including X-ray
sensitive materials, black-and-white photosensitive materials,
photosensitive materials for plate-making, photographic paper, and
so on.
The silver halide emulsions of this invention do not have any
particular limitation as to additives (including binders, chemical
sensitizers, spectral sensitizers, stabilizers, gelatin hardeners,
surfactants, antistatic agents, polymer latexes, matting agents,
color couplers, ultraviolet absorbents, discoloration inhibitors
and dyes), supports, coating methods, exposure methods and
development-processing methods of the photographic materials using
these emulsions. For details with respect to the additives, one can
refer to the descriptions, e.g., in Research Disclosure, Vol. 176,
Item 17643 (RD-17643), ibid., Vol. 187, Item 18716 (RD-18716), and
ibid., Vol. 225, Item 22534 (RD-22534), as set forth below.
______________________________________ Kind of Additives RD 17643
RD 18716 RD 22534 ______________________________________ 1.
Chemical Sensitizers Page 23 Page 648, Page 24 right column 2.
Sensitivity Page 648, Increasing Agents right column 3. Spectral
Sensitizers Pages 23 Page 648, Page 24 and Supersensitizers to 24
right to 28 column to page 649, right column 4. Brightening Agents
Page 24 5. Antifoggants and Pages 24 Page 649, Page 24 Stabilizers
to 25 right and 31 column 6. Light-Absorbers, Pages 25 Page 649,
Filter Dyes and to 26 right column UV Ray Absorbers to page 650,
left column 7. Stain Inhibitors Page 25, Page 650, right left
column column to right column 8. Dye Image Page 25 Page 32
Stabilizers 9. Hardeners Page 26 Page 651, Page 28 left column 10.
Binders Page 26 Page 651, left column 11. Plasticizers and Page 27
Page 650, Lubricants right column 12. Coating Aids and Pages 26
Page 650, Surfactants to 27 right column 13. Antistatic Agents Page
27 Page 650, right column 14. Color Couplers Page 25 Page 649 Page
31 ______________________________________
The couplers to be used in this invention should desirably be
rendered nondiffusible through the use of a hydrophobic group
functioning as a ballast group, or by assuming a polymerized form.
Further, two-equivalent couplers which have a coupling group to be
eliminated at their coupling active site are preferred to
four-equivalent ones which have a hydrogen atom at their coupling
site from the standpoint of reduction in silver coverage.
Furthermore, couplers which can form dyes of moderate
diffusibility, colorless couplers, couplers capable of releasing a
development inhibitor upon development (so-called DIR couplers) or
couplers capable of releasing a development accelerator upon
development can be also used.
Typical examples of yellow couplers which can be used in this
invention include oil-protected acylacetamide couplers.
Such couplers are represented by yellow couplers having a
splitting-off group of the type which is attached to the coupling
active site via its oxygen or nitrogen atom. The
.alpha.-pivaloylacetanilide type couplers are excellent in fastness
of the colored dyes, particularly in the light fastness thereof,
and the .alpha.-benzoylacetanilide type couplers generally form
dyes of high color density.
Magenta couplers which can be used in this invention include
oil-protected indazolone or cyanoacetyl couplers, preferably those
of the 5-pyrazolone type and those of the pyrazoloazole type, such
as pyrazolotriazoles. Among the 5-pyrazolone type couplers, those
in which the 3-position is sustituted by an arylamino or acylamino
group are preferred from the viewpoint of the hue or the color
density of the colored dyes.
Imidazo[1,2-b]pyrazoles disclosed in U.S. Pat. No. 4,500,630 are
favored because of the lower yellow side absorption of the colored
dyes and the light fastness thereof, and those particular preferred
in these respects are the pyrazolo[1,5-b][1,2,4]triazoles disclosed
in U.S. Pat. No. 4,540,650.
Cyan couplers which can be used in this invention include
oil-protected naphthol and phenol couplers. Preferred cyan couplers
include the naphthol couplers disclosed in U.S. Pat. No. 2,474,293,
and especially preferred ones are two-equivalent naphthol couplers
having a splitting-off group of the type which is attached to the
coupling active site via its oxygen atom, as disclosed in U.S. Pat.
Nos. 4,052,212, 4,146,396, 4,228,233 and 4,296,200.
Naphthol couplers in which the 5-position is substituted by a
sulfonamido group, an amido group or the like (as disclosed in
JP-A-60-237448, JP-A-61-153640, JP-A-61,-145557) are preferably
used in this invention because of excellence in fastness of the
developed color images.
Couplers which form dyes with an appropriate diffusibility can be
used additionally for the purpose of improving graininess. As for
the couplers of this kind, examples of magenta couplers are
disclosed in U.S. Pat. No. 4,1336,237 and British Patent 2,125,570,
and those of yellow, magenta and cyan couplers are disclosed in
European Patent 96,570 and German Patent (OLS) No. 3,234,533.
Couplers releasing a development inhibitor with the progress of
development, or DIR couplers, may be incorporated in the emulsions
of this invention.
The DIR couplers which are preferred in combination with this
invention include DIR couplers which deactivate a developer, as
disclosed in JP-A-57-151944; DIR couplers of the timing type, as
disclosed in U.S. Pat. No. 4,248,962 and JP-A-57-154234; and DIR
couplers of the reacting type, as disclosed in JP-A-60-184248.
Especially favored ones among the DIR couplers of the above-cited
types are those of the developer deactivating type, as disclosed,
e.g., in JP-A-57-151944, JP-A-58-217932, JP-A-60-218644,
JP-A-60-225156 and JP-A-60-233650; and those of the reacting type,
as disclosed, e.g., in JP-a-60-184248.
Compounds releasing imagewise a nucleating agent, or a development
accelerator or a precursor thereof (hereinafter abbreviated as
"development accelerator or the like") upon development can be used
in the photographic materials of this invention. Typical examples
of such compounds are given in British Patents 2,097,140 and
2,131,188, and include couplers releasing a development accelerator
or the like by the coupling reaction with an oxidized aromatic
primary amine developer, or DAR couplers.
Suitable examples of high boiling organic solvents to be used for
the dispersion of color couplers include phthalic acid esters (such
as dibutyl phthalate, dicyclohexyl phthalate,
di-2-ethylhexylphthalate, decyl phthalate, etc.), phosphoric or
phosphonic acid esters (such as triphenyl phosphate, tricresyl
phosphate, 2-ethylhexyl diphenyl phosphate, tricyclohexyl
phosphate, tri-2-ethylhexyl phosphate, tridecyl phosphater triethyl
phosphate, trichloropropyl phosphate, di-2-ethylhexyl phenyl
phosphate, etc.), benzoic acid esters (such as
2-ethylhexylbenzoate, dbdecylbenzoate,
2-ethylhexyl-p-hydroxybenzoate, etc. ), amides (such as
diethyldodecanamide, N-tetradecylpyrrolidone, etc.), alcohols or
phenols (such as isostearyl alcohol, 2,4-di-tert-amylphenol, etc.),
aliphatic carboxylic acid esters (such as dioctylazelate, -glycerol
tributyrate, isostearyl lactate, trioctyl tosylate, etc.), aniline
derivatives (such as N,N-dibutyl-2-butoxy-5-tert-octylaniline,
etc.), hydrocarbons (such as paraffin, dodecylbenzene,
diisopropylnaphthalene, etc.), and so on. In addition, organic
solvents having a boiling point of about 30.degree. C. or above,
preferably from 50.degree. C. to about 160.degree. C., can be used
as auxiliary solvents. Typical examples of auxiliary solvents
include ethyl acetate, butyl acetate, dthyl propionate, methyl
ethyl ketone, cyclohexanone, 2-ethoxyethyl acetate,
dimethylformamide, and so on.
As for the gelatin hardener, active halogen-containing compounds
(e.g., 2,4-dichloro-6-hydroxy-1,3,5-triazine and the sodium salt
thereof) and active vinyl compounds (e.g.,
1,3-bisvinylsulfonyl-2-propanol,
1,2-bis(vinylsulfonylacetamide)ethane, vinyl polymers having
vinylsulfonyl group in their side chains) are preferred, because
they can harden rapidly hydrophilic colloids such as gelatin to
ensure stable photographic characteristics. Also,
N-carbamoylpyridinium salts (e.g., 1-morpholinocarbonyl-3-pyridinio
methanesulfonate) and haloamidinium salts (e.g.,
1-(1-chloro-1-pyridinomethylene)pyrrolidinium
2-naphthalenesulfonate) are excellent because of their high
hardening speeds.
After development and subsequent bleach-fix or fixation processing,
color photographic materials using the silver halide photographic
emulsions of this invention are generally subjected to a washing or
stabilization processing.
In general, the washing step is performed in accordance with a
counter-current method using two or more processing tanks for the
purpose of saving water. On the other hand, the stabilization step
can be performed instead of the washing step, in which a multistage
counter current stabilization method as described in JP-A-57-8543
can be used typically.
The color developer to be used in the development processing of the
photographic materials of this invention is preferably an alkaline
aqueous solution containing as a main component an aromatic primary
amine developing agent. As for the color developing agent,
p-phenylenediamine compounds are preferably used, although
aminophenol compounds are also useful. Typical examples of
p-phenylenediamine type developing agents include
3-methyl-4-amino-N,N-diethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-hydroxy-ethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-methane-sulfonamidoethylaniline,
3-methyl-4-amino-N-ethyl-N-.beta.-methoxyethylaniline, and the
sulfates, hydrochlorides or p-toluenesulfonates of the above-cited
agents. These compounds can be used in combination with two or more
thereof, if desired.
In carrying out reversal processing, black and white development is
generally succeeded by color development. For the black and white
developer, dihydroxybenzenes such as hydroquinone, 3-pyrazolidones
such as 1-phenyl-3-pyrazolidone, aminophenols such as
N-methyl-p-aminophenol, and other known black-and-white developing
agents can be used alone or as a mixture of two or more
thereof.
In general, the pH of these color developers and black and white
developers is within the range of 9 to 12. Each of these developers
is supplied with not more than 3 l portions of a replenisher per
m.sup.2 of photographic materials processed therein. In the case
where the replenisher has a reduced bromine ion concentration, the
replenishing amount can be lowered to 500 ml or less.
The photographic emulsion layers are generally subjected to
bleach-processing after the color development. The
bleach-processing may be carried out simultaneously with
fixation-processing (bleach-fix processing), or separately
therefrom. For the purpose of further increasing the photographic
processing speed, the bleach-processing may be succeeded by
bleach-fix processing. As a bleaching agent, aminopolycarboxylic
acid-Fe(III) complex salts are particularly useful in both the
bleaching bath and bleach-fix bath. The pH of the bleaching or
bleach-fix bath using an aminopolycarboxylic acid-Fe(III) complex
salt generally ranges from 5.5 to 8. However, these processing
baths may be adjusted to a still lower pH in order to increase the
processing speed.
In the bleaching bath, the bleach-fix bath and the prebaths
thereof, a bleach accelerator can be used, if needed. As useful
bleach accelerators, compounds containing a mercapto group or a
disulfide linkage are preferred because of their great effect. Of
such compounds, those disclosed in U.S. Pat. No. 3,893,858, German
Patent 1,290,812 and JP-A-53-95630 are favored in particular. In
addition, the compounds disclosed in U.S. Pat. No. 4,552,834 are
also advantageous. These bleach accelerators may be incorporated
into photographic materials.
The silver halide color photographic materials of this invention,
as described above, are generally subjected to washing and/or
stabilization processing after the desilvering processing. The
volume of washing water to be used in the washing processing can be
chosen from a wide range because it depends on characteristics of
the photographic materials to be washed (e.g., whether couplers are
incorporated therein, or not), the end-use purpose of the
photographic materials to be washed, the temperature of the washing
water, the number of washing tanks (the number of washing stages),
the method for replenishing the washing water (e.g., whether the
method for washing stages is counter current or not), and other
various conditions. Among these conditions, the relationship
between the numer of washing tanks and the water volume can be
determined in accordance with the method described in Journal of
the Society of Motion Picture and Television Engineers, vol. 64,
pp. 248-253.(May 1955).
This invention will be illustrated in greater detail by reference
to the following examples. However, the invention should not be
construed as being limited to these examples. All parts, percents,
and ratios are by weight unless otherwise indicated.
EXAMPLE 1
Protective Colloid Polymer
The protective colloids employed in this example are cited
below.
P-1 Alkali-processed ossein gelatin
(weight average molecular weight: 100,000)
P-2 Low molecular weight gelatin
(weight average molecular weight: 10,000)
P-3 Polyvinyl alcohol ##STR8## (weight average molecular weight:
70,000)
P-4 Vinyl polymer containing azaindenyl groups ##STR9## (weight
average molecular weight: 60,000)
P-5 1-Vinyl-2-methylimidazole polymer ##STR10## (weight average
molecular weight: 20,000)
P-6 Copolymer of acrylamide and 1-vinyl-2-methyl-imidazole
##STR11## (weight average molecular weight: 50,000)
P-7 Vinyl polymer containing thioether groups ##STR12## (weight
average molecular weight: 70,000)
P-8 Polyvinyl pyrrolidone ##STR13## (weight average molecular
weight: 50,000)
P-9 Copolymer of vinyl alcohol and vinyl pyrrolidone ##STR14##
(weight average molecular weight: 60,000)
P-10 ##STR15## (weight average molecular weight: 60,000)
Superfine Grain Silver Bromide Emulsion (1-A)
Comparison
600 ml of an aqueous solution containing 100 g of silver nitrate,
600 mi of an aqueous solution containing 72 g of potassium bromide
and 2,400 ml of a 3 wt % aqueous solution of the foregoing gelatin
P-1 were injected at a uniform speed into a mixing device as shown
in FIG. 1 over a 150-minute period in accordance with the triple
jet method. The gelatin had a physical retardativity value of 12.
The residence time of the injected solutions in the mixing device
was 10 seconds. The agitation impeller was rotated at a speed of
1,000 r.p.m. The average size of the fine grains of silver bromide
expelled from the mixing vessel was determined to be 0.03 .mu.m by
observation with a direct transmission electron microscope of
20,000 magnification. The temperature inside the mixing device was
kept at 35.degree. C., and the fine grains formed in the mixing
vessel were introduced continuously into a collection vessel. At
the conclusion of the collection, the obtained superfine grain
emulsion was heated up to 50.degree. C. and kept for 60 minutes.
Again, the grain size of the thus ripened emulsion was examined by
means of the direct transmission electron microscope of
20,000.times.magnification. Thereby, it was determined that the
average grain size increased to 0.055 .mu.m.
Silver Bromide Superfine Grains (1-B)
Comparison
Another preparation was tried under the same conditions as were
used with the preparation of the foregoing emulsion (1-A), except
the temperature in the mixing device was set at 20.degree. C.
However, fine grain formation ended in a failure because of the
gelation of the gelatin solution in the mixing device, which was
caused by setting the temperature in the mixing device at
20.degree. C. More specifically, it is necessary to lower the
temperature in the mixing device, for the formation of fine grains
with a still smaller size, but the formation of fine grains has
nevertheless turned out to be impossible so long as the gelatin P-1
was used as protective colloid.
Silver Bromide Superfine Grains (1-C)
Comparison
Instead of using the gelatin P-1. the foregoing low molecular
weight gelatin P-2 was used as protective colloid in preparing
another emulsion under the same conditions as were used in the
preparation of emulsion (1-B) . The low molecular weight gelatin
had a physical retardativity value of 7. The solution of the
gelatin P-2 did not gel at all under a temperature of 20.degree.
C., and enabled the formation of superfine grains.
Superfine Grain Silver Bromide Emulsions (1-D) to (1-K)
Emulsions from (1-D) to (1-K) were prepared under the same
conditions as described above (wherein a temperature of the mixing
device was set at 20.degree. C.), except the synthetic polymers of
this invention, from P-3 to P-10, functioning as protective
colloid, were used respectively instead of the foregoing
gelatins.
Fine Grain Silver Bromide Emulsion (1-L)
Comparison
1,500 ml of water and 35 g of the gelatin P-1 were placed in a
reaction vessel, and stirred vigorously. 600 ml of an aqueous
solution containing 100 g of silver nitrate and 600 ml of an
aqueous solution containing 75 g of potassium bromide were added
simultaneously to the stirred gelatin solution at a uniform speed
over a 50-minute period under a silver potential of +40 mV
(relative to a saturated calomel electrode) in accordance with the
controlled double jet method. The reaction vessel was kept at
35.degree. C. The grain size just after the conclusion of the
addition was 0.05 .mu.m. The temperature of the reaction vessel was
raised to 50.degree. C. at the conclusion of the addition, and kept
there for 60 minutes. Thus, the grain size increased to 0.06
gm.
The conditions and results of the above-described emulsion grain
formation are summarized below in Table 1.
TABLE 1 ______________________________________ Average Average
Temp. Grain Grain of Size Just af- Size after Protec- Mixing ter
Expulsion 60-minute Emul- tive Device from Mixing Lapse at sion
Colloid (.degree.C.) Device (.mu.m) 50.degree. C. (.mu.m) Note
______________________________________ 1-A P-1 35 0.03 0.06 Compar-
ison 1-B " 20 -- -- Compar- ison 1-C P-2 " 0.015 0.06 Compar- ison
1-D P-3 " 0.01 0.01 Invention 1-E P-4 " 0.015 0.02 " 1-F P-5 " 0.01
0.01 " 1-G P-6 " 0.015 0.02 " 1-H P-7 " 0.015 0.015 " l-I P-8 "
0.01 0.01 " 1-J P-9 " 0.01 0.01 " 1-K P-10 " 0.02 0.03 " 1-L P-1 35
0.05* 0.06 Compar- ison ______________________________________ *The
average size of the grains present in the reaction vessel just
after the conclusion of the addition.
All of the protective colloids from P-3 to P-10 had physical
retardance values of 40 or more, whereas the physical retardance
values of the gelatin P-1 and the gelatin P-2 were 12 and 7,
respectively.
In the cases where the alkali-processed gelatin P-1 and the low
molecular weight gelatin P-2 were used, superfine grain emulsions
with sizes of 0.03 .mu.m and 0.015 .mu.m respectively were obtained
just after the expulsion from the mixing device, but these average
grain sizes both increased to 0.06 .mu.m by the 60-minute aging
process at 50.degree. C. This result implies that in the lapse of
time required for washing, redispersion, chemical sensitization,
storage, redissolution and solution of the emulsion, which are all
essential steps in preparation of a photographic material, an
increase in grain size takes place to make it impossible to obtain
a photographic material containing superfine grains. On the other
hand, the emulsions of this invention, from (1-D) to (1-K), had
either no increase at all in grain size or only a very slight
increase in grain size. Therefore, it is apparent that materials
containing superfine grain emulsions can be prepared with this
invention. Also, it is apparent from the result of emulsion (1-L)
that according to the conventional method of not using any mixing
device, the grain growth which took place failed to provide
superfine grains.
EXAMPLE 2
Superfine Grain Silver Chloride Emulsion (2-1)
Comparison
400 ml of an aqueous solution containing 100 g of silver nitrate,
400 ml of an aqueous solution containing 36 g of sodium chloride
and 1,600 ml of a 3 wt % aqueous solution of the-foregoing ossein
gelatin P-1 were injected at a uniform speed into a mixing device
as shown in FIG. 1 over a 100-minute period in accordance with the
triple jet method. The gelatin had a physical retardativity value
of 12. The residence time of the injected solutions in the mixing
device was 10 seconds. The agitation impeller was rotated at a
speed of 1,500 r.p.m. The average size of the fine grains of silver
chloride expelled from the mixing vessel was determined to be 0.05
.mu.m by observation with a direct transmission electron microscope
of 20,000.times.magnification. The temperature inside the mixing
device was kept at 30.degree. C., and the fine grains formed in the
mixing vessel were introduced continuously into a collection
vessel. At the conclusion of the addition, the obtained superfine
grain emulsion was heated up to 50.degree. C. and kept at that
temperature for 60 minutes. The grain size of the thus ripened
emulsion was examined by means of the direct transmission electron
microscope of 20,000.times.magnification. Thereby, it was
determined that the average grain size increased to 0.11 .mu.m.
Silver Chloride Superfine Grain Emulsion (2-2)
Comparison
Another preparation was tried under the same conditions as were
used with the preparation of the foregoing emulsion (2-1), except
the temperature in the mixing device was set at 18.degree. C.
However, fine grain formation ended in a failure because of the
gelation of the gelatin solution in the mixing device, which was
caused by setting the temperature in the mixing device at
18.degree. C. More specifically, it is necessary to lower the
temperature in the mixing device, for the formation of fine grains
with a still smaller size, but the formation of fine grains has
nevertheless turned out to be impossible so long as the gelatin P-1
was used as protective colloid.
Silver Chloride Superfine Grain Emulsion (2-3)
Comparison
Instead of using the gelatin P-1, the foregoing low molecular
weight gelatin P-2 was used as the protective colloid in preparing
another emulsion under the same conditions as were used in the
preparation of emulsion (2-2). The low molecular weight gelatin had
a physical retardativity value of 7. The solution of the gelatin
P-2 did not gel at all under a temperature of 18.degree. C., and
enabled the formation of superfine grains.
Silver Chloride Superfine Grain Emulsion (2-4)
Invention
Still another emulsion was prepared in the same manner as emulsion
(2-1) was prepared, except 0.012 mol of the grain-growth retarder
I-1 was added to 1,600 ml of the 3 wt % aqueous solution of the
ossein gelatin P-1.
Silver Chloride Superfine Grain Emulsions (2-5) to (2-13)
Invention
Emulsions relating-to this invention, identified as emulsions (2-5)
to (2-13), were prepared under the same conditions as described
above (wherein the temperature in the mixing device was set at
30.degree. C.), except the grain-growth retarder I-1 was replaced
by the grain-growth retarders shown in Table 2, respectively.
Silver Chloride Superfine Grain Emulsion (2-14)
Invention
An emulsion was prepared in the same manner as the emulsion (2-3),
except 0.012 mol of the grain-growth retarder I-1 was additionally
contained in 1,600 ml of the low molecular weight gelatin (P-2)
solution.
Silver Chloride Superfine Grain Emulsions (2-15) to (2-23)
Invention
Emulsion relating to this invention, identified as emulsions (2-15)
to (2-23), were prepared under the same conditions as described
above (wherein a temperature of the mixing device was set at
18.degree. C.), except the grain-growth retarder I-1 was replaced
by the grain-growth retarders shown in Table 2, respectively.
Silver Chloride Fine Grain Emulsion (2-24)
Comparison
1,500 ml of water and 35 g of the gelatin P-1 were placed in a
reaction vessel, and stirred vigorously. 600 ml of an aqueous
solution containing 100 g of silver nitrate and 600 ml of an
aqueous solution containing 75 g of sodium chloride were added
simultaneously to the stirred gelatin solution at a uniform speed
over a 50-minute period under a silver potential of +190 mV
(relative to a saturated calomel electrode) in accordance with the
controlled double jet method. The reaction vessel was kept at
30.degree. C. The grain size just after the conclusion of the
addition was 0. 08 .mu.m. The temperature of the reaction vessel
was raised to 50.degree. C. at the conclusion of the addition and
kept there for 20 minutes. Thus, the grain size increased to 0.11
m.
The conditions and results of the above-described emulsion grain
formation are summarized below in Table 2.
TABLE 2 ______________________________________ Average Average
Temp. Grain Grain of Size Just af- Size after Grain Mixing ter
Expulsion 60-minute Emul- Growth Device from Mixing Lapse at sion
Retarder (.degree.C.) Device (.mu.m) 50.degree. C. (.mu.m) Note
______________________________________ 2-1 -- 30 0.05 0.11 Compar-
ison 2-2 -- 18 -- -- Compar- ison 2-3 -- " 0.025 0.11 Compar- ison
2-4 I-1 30 0.04 0.04 Invention 2-5 I-7 " " " " 2-6 I-9 " 0.05 0.05
" 2-7 I-15 " " 0.05 " 2-8 I-22 " 0.04 0.04 " 2-9 II-2 " 0.05 0.05 "
2-10 II-5 " " 0.05 " 2-11 II-12 " 0.05 0.05 " 2-12 II-23 " " " "
2-13 III-1 " 0.05 0.05 " 2-14 I-1 18 0.015 0.015 " 2-15 I-7 " " " "
2-16 I-9 " 0.03 0.03 " 2-17 I-15 " 0.02 0.02 " 2-18 I-22 " 0.02
0.025 " 2-19 II-2 " 0.025 0.03 " 2-20 II-5 " " 0.025 " 2-21 II-12 "
0.02 0.025 " 2-22 II-23 " " " " 2-23 III-1 " 0.025 0.03 " 2-24 --
30 0.08* 0.11 Compar- ison ______________________________________
*The average size of the grains present in the reaction vessel just
after the conclusion of the addition.
All of the grain-growth retarders of this invention had physical
retardance values of 50 or more,, whereas the physical retardance
values of the gelatin P-1 alone and the gelatin P-2 alone were 12
and 7, respectively.
Even in the cases where any grain-growth retarder was not used,
superfine silver chloride grains were obtained just after the
expulsion from the mixing device, particularly in the case where
the temperature in the mixing device was low, but the average grain
size increased to 0.06 .mu.m in every case by the 20-minute aging
process at 50.degree. C. This result implies that in the lapse of
time required for washing, redispersion, storage, redissolution and
solution of the emulsion, which are all essential steps in
preparation of a photographic material, an increase in grain size
takes place to make it impossible to obtain a photographic material
containing superfine grains. On the other hand, all the emulsions
of this invention, from (2-4) to (2-13) (mixing device temperature:
30.degree. C.) and from (2-14) to (2-23) (mixing device
temperature: 18.degree. C.), had either no increase at all in grain
size or only a very slight increase in grain size. Therefore, it is
apparent that materials containing superfine grain emulsions can be
prepared with this invention. Also, it is apparent from the result
of emulsion (2-24) that according to the conventional method of not
using any mixing device, the grain growth which took place failed
to provide preparing superfine grains.
EXAMPLE 3
Silver Bromide Superfine Grain Emulsion (3-A)
Invention
Superfine grains were formed in the same manner as those of silver
bromide emulsion (1-C) in Example 1, except 0.013 mol of a
sensitizing dye (IV-5) was additionally contained in 2,400 ml of a
3 wt % of aqueous solution of the protective colloid P-2 (mixing
device temperature: 20.degree. C.).
Other emulsions, identified as (3-B) to (3-F), were prepared under
the same conditions as described above, except the sensitizing dye
IV-5 was replaced by sensitizing dyes set forth in Table 3. The
conditions under which grains of each emulsion grew, and the result
therefrom, are shown in Table 3.
TABLE 3 ______________________________________ Average Average
Temp. Grain Grain of Size Just af- Size after Sensi- Mixing ter
Expulsion 60-minute Emul- tizing Device from Mixing Lapse at sion
Dye (.degree.C.) Device (.mu.m) 50.degree. C. (.mu.m) Note
______________________________________ 1-C -- 20 0.015 0.06 Compar-
ison 3-A IV-5 " 0.015 0.02 Invention 3-B IV-9 " 0.015 0.015 " 3-C
IV-10 " 0.015 0.015 " 3-D IV-31 " 0.01 0.01 " 3-E V-5 " 0.01 0.01 "
3-F V-12 " 0.01 0.015 " ______________________________________
All of the sensitizing dyes used herein had a physical retardance
value of 40 or more.
As can be seen from Table 3, the superfine grains with an average
size of 0.015 .mu.m were obtained even in the absence of any
sensitizing dye just after the expulsion from this mixing device,
but the grains formed under the condition markedly increased in
size to 0.06 .mu.m by the 60-minute aging process at 50.degree. C.
This result implies that in the, lapse of time required for
washing, redispersion, chemical sensitization, storage,
redissolution and solution of the emulsion, which are all essential
steps in preparation of a photographic material, an increase in
grain size takes place to make it impossible to obtain a
photographic material containing superfine grains. On the other
hand, the emulsions of this invention, from (3-A) to (3-F), had
either no increase at all in grain size or only a very slight
increase in grain size. Therefore, it is apparent that materials
containing superfine grain emulsions can be prepared with this
invention.
EXAMPLE 4
Superfine grain emulsions were prepared by a process which
comprised forming superfine grains in a mixing device, continuously
expelling the formed superfine grain emulsion from the mixing
device, and adding a protective colloid polymer or grain-growth
retarder satisfying the requirement of this invention to the
emulsion just after the expulsion.
More specifically, as shown in FIG. 2, superfine grains were formed
in the first mixing device and immediately introduced into the
second mixing device (having the same structure as shown in FIG.
2). A protective colloid polymer capable of retarding the
grain-growth or a grain-growth retarder was added to the second
mixing device concurrently with the introduction of the superfine
grains, and mixed with the emulsion therein. The resulting mixture
was expelled from the second mixing device and introduced into a
collection vessel.
The compounds used in this example are illustrated below.
Silver Chloride Superfine Grain Emulsions (4-1) to (4-3)
Silver chloride superfine grain emulsions were formed in the same
manner as the superfine grain emulsion (2-3) in Example 2 (mixing
device temperature: 18.degree. C.), and each emulsion expelled from
the mixing device was injected into the second mixing device in
less than 10 seconds. 400 ml of a 10 wt % aqueous solution of the
polymer P-3 was added to the second mixing device at a uniform
speed concurrently with the injection of the emulsion, over a
100-minute period to prepare an emulsion (4-1).
Emulsions (4-2) and (4-3) were prepared in the same manner as
described above, except the polymers P-5 and P-8 were used in the
place of the polymer P-3.
Silver Chloride Superfine Grain Emulsions (4-4) to (4-11)
An emulsion (4-4) was prepared in the same manner as the foregoing
emulsion (4-1), except 100 ml of a solution containing 0.012 mol of
the grain-growth retarder I-1 instead of the foregoing polymer
solution was added to the second mixing device at a uniform speed
over a 100-minute period.
Further, emulsions from (4-5) to (4-11) were prepared in the same
manner as described above, except that the grain-growth retarders
set forth in Table- 4 were used in the place of the grain-growth
retarder I-1, respectively.
At the conclusion of the addition, the temperature of each emulsion
was raised to 50.degree. C. and kept there for 60 minutes. Grain
sizes were measured just after the expulsion from the second mixing
device and after the 60-minute aging process at 50.degree. C. The
results obtained are shown in Table 4.
TABLE 4 ______________________________________ Grain Size Grain
Size Temp. Just after after of 1st Expulsion 60-minute Mixing from
2nd Mix- Lapse Emul- Addi- Device ing Device at 50.degree. C. sion
tive (.degree.C.) (.mu.m) (.mu.m) Note
______________________________________ 4-1 P-3 18 0.025 0.025
Invention 4-2 P-5 " " 0.025 " 4-3 P-8 " " 0.03 " 4-4 I-1 " " 0.025
" 4-5 I-7 " " 0.03 " 4-6 II-5 " " 0.025 " 4-7 II-23 " " 0.025 " 4-8
IV-9 " " 0.03 " 4-9 IV-31 " " 0.035 " 4-10 V-5 " " 0.025 " 4-11
V-12 " " 0.025 " 2-3 -- " 0.025* 0.11 Compar- ison
______________________________________ *Grain size just after the
expulsion from the first mixing device for grain formation.
As can be seen from Table 4, the emulsion (2-3) presented for
comparison had a very small grain size of 0.025 .mu.m just after
the expulsion from the first mixing device for grain formation, but
the grain size increased to 0.11 .mu.m by the 60-minute aging
process at 50.degree. C. This result implies that in the lapse of
time required for washing, redispersion, storage, redissolution,
chemical sensitization, and dissolution of the emulsion, which are
all essential steps in preparation of a photographic material, an
increase in grain size takes place to make it impossible to obtain
a photographic material containing superfine grains. On the other
hand, the present emulsions, from (4-1) to (4-11) (mixing device
temperature: 18.degree. C.), had either no increase at all in grain
size or only a very slight increase in grain size. Therefore, it is
apparent materials containing superfine grain emulsions can be
prepared with this invention.
EXAMPLE 5
Silver halide photographic materials were prepared by a process
which comprised forming superfine grains in a first mixing device,
expelling the formed grains continuously from the mixing device,
immediately adding a sensitizing dye satisfying the requirement of
this invention to the expelled grains, and coating the thus
obtained superfine grain emulsion on a support. That is, the
superfine grain emulsion was prepared in the same manner as in
Example 4.
In this example, the preparation of silver halide photographic
materials using the superfine grain emulsions made in the
above-described process and image forming methods using these
photographic materials were examined.
By analogy with the silver bromide superfine grains (1-C) described
in Example 1, an emulsion having an average grain size of 0.015
.mu.m just after the expulsion from the mixing device was prepared
as follows: 600 ml of an aqueous solution containing 100 g of
silver nitrate, 600 ml of an aqueous solution containing 72 g of
potassium bromide and 2,400 ml of a 3 wt % aqueous solution of the
low molecular weight gelatin P-2 were injected simultaneously into
the mixing device as shown in FIG. 1 at a uniform speed over a
150-minute period in accordance with the triple jet method
(residence time of each injected solution in the mixing device: 10
seconds; rotation speed of the agitation impeller: 1,000 r.p.m.;
mixing device temperature: 20.degree. C.). The superfine grains
expelled from the mixing device were immediately introduced into
the second mixing device (as shown in FIG. 3) and, at the same
time, were mixed with a methanol solution containing a sensitizing
dye capable of retarding the grain growth.
More specifically, 500 ml of a mixture containing a superfine grain
emulsion with a grain size of 0.015 .mu.m (containing 0.082 mol of
silver bromide) was added to 1,600 ml of a stirred methanol
solution of the sensitizing dye IV-9 (sensitizing dye
concentration: 0.002 M). The gelatin condensed immediately upon
mixing to result in the generation of turbidity, so the stirring
was stopped. The precipitates were generated while the mixture was
left standing, and the supernatant thereof was removed to effect
desalting and condensation.
5 g of an alkali-processed gelatin P-1, a surfactant, a hardener
and antiseptics were added to the thus obtained precipitates. Water
was added thereto in such an amount as to adjust the total volume
to 100 ml. Then, the mixture was stirred while being heated at
50.degree. C. for homogeneous dispersion. Further, the obtained
dispersion was kept at 40.degree. C. and coated on a cellulose
triacetate film provided with a subbing layer so that the resulting
layer had a thickness of 7 .mu.m and a silver coverage of 5
g/m.sup.2.
Thus, a silver halide photographic material was produced, and it
was named Sample (5-2). Another sample (5-1) was prepared in the
same manner as sample (5-2), except the sensitizing dye IV-9 was
not used. In addition, other samples (5-3), (5-4) and (5-5) were
prepared in the same manner as sample (5-2), except the sensitizing
dye IV-9 was replaced by the sensitizing dyes IV-31, V-5 and V-12,
respectively, in the corresponding amounts. Also, samples for
comparison, (5-12), (5-13), (5-14) and (5-15), were prepared in the
same manner as sample (5-1), except the sensitizing dyes IV-9,
IV-31, V-5 and V-12 were added in their own optimal amounts,
respectively, just before the coating.
The sizes of the silver bromide grains contained in the thus
prepared silver halide photographic materials were measured using
the foregoing method, and the results obtained were set forth in
Table 5-1.
TABLE 5-1 ______________________________________ Addition Time
Grain Size Sample Additive of Additive (.mu.m) Note
______________________________________ 5-1 -- -- 0.06 Comparison
5-2 IV-9 Just after 0.020 Invention Grain Formation 5-3 IV-31 Just
after 0.015 " Grain Formation 5-4 V-5 Just after 0.015 " Grain
Formation 5-5 V-12 Just after 0.015 " Grain Formation 5-12 IV-9
Just before 0.06 Comparison Coating 5-13 IV-31 Just before 0.06 "
Coating 5-14 V-5 Just before 0.06 " Coating 5-15 V-12 Just before
0.06 " Coating ______________________________________
As can be seen from Table 5-1, the sizes of the silver halide
grains contained in the silver halide photographic materials in
accordance with the embodiments of this invention were equal to or
slightly larger than those just after the grain formation because
of the effect which the additives of this invention exerted on
newly-formed grains, whereas in sample (5-1), which did not use any
of the additives of this invention, and in samples (5-12), (5-13),
(5:-14) and (5-15), which used the additives of this invention out
of accordance with every embodiment of this invention, growth of
the grains was not inhibited to result in a great increase of grain
size to 0.06 .mu.m.
IMAGE FORMATION EXAMPLE 5-A
For the purpose of proving the utility of the silver halide
photographic materials of this invention in the recording of
holographic images, phase holograms were formed using a process
which comprised dividing Ar-laser beams having a wavelength of 488
nm into two luminous fluxes by a half mirror to generate an
interference fringe inside a prism brought into contact with a
silver halide photographic material through xylene and thereby
recording images. Since vibrations of samples and the optical
system have a great influence on the results of the image
recording, this experiment was carried out on an antivibration
table. Other specific operations in the experiment were performed
by consulting the descriptions in a book entitled Fundamentals and
Experiments of Holocraphy, on pages 85 to 184, edited by Akira
Matsushita, written by Norimitsu Hirai, published by Kyoritsu
Shuppan in 1979. In the formation of holograms, the diffraction
efficiency upon the reproduction of images (brilliancy of
reproduced images) becomes greater when a photographic material
having a higher resolving power is used.
An improvement in diffraction efficiency can be achieved by using
the silver halide photographic materials of this invention, as is
demonstrated below in this experiment.
Each of the samples (5-4), (5-5), (5-14) and (5-15), which had a
high sensitivity to light having a wavelength of 488 nm, was
exposed to the interference fringe (intervals: about 0.2 .mu.m) of
light having a wavelength of 488 nm by performing the
above-described operations. The thus exposed materials were
developed in the following manner. The exposure of each sample was
carried out under different conditions of illuminance, and the
optimal exposure for achieving the maximum diffraction efficiency
was determined thereby. The data for diffraction efficiency shown
in Table 5-2 are values determined under the respective optimal
exposure conditions.
______________________________________ Processing Steps:
Development 20.degree. C. 3 minutes Stop bath 20.degree. C. 1
minute Bleaching 20.degree. C. 10 minutes Washing 20.degree. C. 2
minutes KI bath 20.degree. C. 2 minutes Washing 20.degree. C. 10
minutes Air drying Formula of Developer: Pyrogallol 6.0 g
L-Ascorbic acid 6.0 g Sodium carbonate 30.0 g H.sub.2 O to make 1.0
l Formula of Stop Bath: 0.5% Aqueous solution of acetic acid
Formula of Bleaching Solution: Sodium ethylenediaminetetra- 100 g
acetatoferrate(III) KBr 10 g H.sub.2 O to make 1.0 l Formula of KI
Bath: KI 2.5 g H.sub.2 O to make 1.0 l
______________________________________
TABLE 5-2 ______________________________________ Addition Time
Diffraction Addition Time Efficiency Sample Additive of Additive
(%) Note ______________________________________ 5-4 V-5 Just after
55 Invention Grain Formation 5-5 V-12 Just after 55 " Grain
Formation 5-14 V-5 Just before 25 Comparison Coating 5-15 V-12 Just
before 25 " Coating ______________________________________
As can be seen from the data set forth in Table 5-2, the holograms
formed by using the photographic materials of this invention
manifested a diffraction efficiency higher than those formed by
using the photographic materials prepared for comparison. These
results demonstrate the utility of the silver halide photographic
materials of this invention in the holographic image recording.
IMAGE FORMATION EXAMPLE 5-B
For the purpose of proving the utility of the silver halide
photographic materials of this invention in recording electron-beam
images with high density, a test pattern constituted by parallel
lines at 0.20 .mu.m intervals was recorded on the silver halide
photographic materials of this invention by the use of electron
beams having a beam diameter of 0.10 .mu.m .phi..
Samples (5-1B) , (5-2B) , (5-4B) , (5-12B) and (5-14B) were
prepared in the same manner as the samples (5-1), (5-2), (5-4),
(5-12) and (5-14), respectively, prepared in Example 5, except the
cellulose triacetate film support was replaced by a polyethylene
terephthalate film provided with a discharge membrane of RbAg.sub.4
I.sub.5 protected by a nitrocellulose film, as shown in FIG. 2 (b)
of JP-B-49-24282, the thickness of the emulsion coat was changed to
1 .mu.m, and the Ag coverage was changed to 0.7 g/m.sup.2. A test
pattern constituted by parallel lines at 0.20 .mu.m intervals was
recorded on each of the thus prepared samples using electron beams
having a beam diameter of 0.10 .mu.m .phi. under an acceleration
voltage of 70 kV. The photographic processing of these samples was
carried out under the following condition.
______________________________________ Processing Steps:
Development 20.degree. C. 5 minutes Stop bath 20.degree. C. 1
minute Fixation 20.degree. C. 5 minutes Washing 20.degree. C. 10
minutes Air drying Formula of Developer: Metol 2.5 g L-Ascorbic
acid 10.0 g NABOX 35.0 g KBr 1.0 g H.sub.2 O to make 1.0 l Formula
of Stop Solution: 0.5% Aqueous solution of acetic acid Formula of
Fixer: Sodium thiosulfate 60.0 g Acetic acid 2.0 g H.sub.2 O to
make 1.0 l ______________________________________
When the thus processed comparison samples (5-1B), (5-12B) and
(5-14B), were observed with a high resolution, field-emission type
scanning electron microscope (Hitachi S-900), the line width of the
recorded test pattern was not uniform and the density of line
pieces in the linked state fluctuated noticeably, because the sizes
of the developed silver grains in these samples (on the order of
about 0.06 .mu.m) were close to the width of the lines constituting
the test pattern. In contrast, in the samples of this invention,
the size of the developed silver halide grains was on the order of
about 0.020 .mu.m in sample (5-2B) and on the order of about 0.015
.mu.m in sample (5-4B), which were definitely smaller than the line
width of the test pattern, resulting in high uniformity in the line
width and in density characteristics of the line pieces in the
linked state on the recorded test pattern. The results of this
experiment demonstrate that the silver halide photographic
materials of this invention are well suited for the high density
recording of electron beam images.
EXAMPLE 6
In this example, image formation using the silver halide
photographic materials of this invention was demonstrated to be
small in variation caused by the handling under daylight and
excellent in tone reproducibility of halftone images.
Preparation of Samples for Comparison
Emulsion 6-a: An aqueous potassium bromide solution containing
8.times.10.sup.-6 mol/mol Ag of (NH.sub.4).sub.3 RhCl.sub.6 and an
aqueous silver nitrate solution were added simultaneously over a
20-minute period to an aqueous gelatin solution kept at 30.degree.
C. During the addition, the pAg was kept at 7.5. Thus, a cubic fine
grain emulsion having an average grain size of 0.06 .mu.m was
prepared. This emulsion was desalted using the flocculation
process, and gelatin and the stabilizer (II-1) were added thereto
in succession.
Emulsion 6-b: An emulsion was prepared in the same manner as
emulsion 6-a, except the addition amount of (NH.sub.4).sub.3
RhCl.sub.6 was changed to 5.times.10.sup.-5 mol/mol Ag.
Emulsion 6-c: An aqueous sodium chloride solution containing
8.times.10.sup.-5 mol/mol Ag of (NH.sub.4).sub.3 RhCl.sub.6 and an
aqueous silver nitrate solution were added simultaneously over a
10-minute period to an aqueous gelatin solution kept at 30.degree.
C. During the addition, the silver potential was kept at 100 mV.
Thus, a cubic silver chloride fine grain emulsion having an average
grain size of 0.10 .mu.m was prepared. This emulsion was desalted
using the flocculation process, and gelatin and the stabilizer
(II-1) were added thereto in succession.
Four kinds of superfine grain emulsions were prepared in the same
manner as the silver bromide super-fine grain emulsions 1-E and 1-K
(see Example 1) and the silver chloride superfine grain emulsions
2-14 and 2-19 (see Example 2), respectively. These emulsions were
desalted using the flocculation process, admixed with gelatin,
chemically sensitized with sodium thiosulfate and chloroauric acid,
and then admixed with the stabilizer (II-1) . Thus, the emulsions
6-d, 6-e, 6-f and 6-g, relating to this invention, were
obtained.
To each of the thus obtained emulsions, from 6-a to 6-c
(Comparison) and from 6-d to 6-g (Invention), polyethylacrylate
latex was added in a proportion of 30 wt % to gelatin on a solids
basis, and 2-bis(vinylsulfonylacetamido)ethane functioning as
hardener was added so as to have a coverage of 80 mg/m.sup.2. Each
of the resulting emulsions was coated on a polyethylene
terephthalate film so as to have a silver coverage of 2.0 g/m.sup.2
and a gelatin coverage of 1 g/m.sup.2. Simultaneously with the
coating of this emulsion, an upper protective layer and a lower
protective layer were coated on said emulsion layer. Therein, the
upper protective layer was constituted by 0.5 g/m.sup.2 of gelatin,
40 mg/m.sup.2 of polymethylmethacrylate particles (size: 4 .mu.m)
as a matting agent, 50 mg/m.sup.2 of silicone oil, and 2.5
mg/m.sup.2 of coating aids including sodium dodecylbenzenesulfongte
and a fluorine-containing surface active agent, C.sub.8 F.sub.17
SO.sub.2 NC.sub.3 H.sub.7 CH.sub.2 CO.sub.2 K, and the lower
protective layer was constituted by 0.8 g/m.sup.2 of gelatin, 100
mg/m.sup.2 of polyethylacrylate latex, 5 mg/m.sup.2 of thioctic
acid, and sodium dodecylbenzenesulfonate. Thus, sample films 601 to
607 were prepared.
Each of the thus obtained samples was subjected to exposure through
an optical wedge by means of a daylight printer P-607 (produced by
Dainippon Screen Mfg. Co., Ltd.)- and then developed at 38.degree.
C. for 20 sec. using an auto processor FG-660F (produced by Fuji
Photo Film Co., Ltd.).
Evaluations of the relative sensitivity, fog after safelight
exposure, and tote reproducibility were made as follows.
Relative Sensitivity: Sensitivity expressed relatively in terms of
the reciprocal of the exposure required for obtaining a density of
1.5.
Fog after Safelight Exposure: Fog generated by the 60-minute
exposure under 200 lux of a white fluorescent lamp FLR 40 SW
(produced by Toshiba Corp.) and the subsequent development.
Tone Reproducibility: Exposure was performed under- a condition in
which a 100 .mu.m-thick PET base was inserted as a spacer between a
wedge having dot area % ranging from 2% to 98% and a sample, and
the evaluation of halftone reproducibility was made thereby. More
specifically, reproducibility of 2% and that of 98% were examined
under the exposure condition in which the halftone dots of 50% were
restored to 50%.
TABLE 6 ______________________________________ Tone Repro- Grain
Relative Safe- ducibility Sam- Emul- Size Sensi- light 2% 98% ple
sion (m) tivity Fog (%) (%) Note
______________________________________ 601 6-a 0.06 263 1.80 99 1
Compar- ison 602 6-b 0.06 100 0.52 99 1 Compar- ison 603 6-c 0.10
90 0.40 100 1 Compar- ison 604 6-d 0.02 100 0.05 98 2 Invention 605
6-e 0.03 251 0.25 98 2 " 606 6-f 0.015 89 0.03 98 2 " 607 6-g 0.03
200 0.20 98 2 " ______________________________________
As can be seen from Table 6-1, the fog caused by safe light
exposure was less in general in the samples using the emulsions of
this invention than in the comparison samples, and the tone
reproducibility was quite good.
EXAMPLE 7
In this example, a method of recording images by subjecting the
silver halide photographic materials of this invention to scanning
exposure with laser beams was demonstrated to be excellent in
fidelity of high density fine image recording.
Preparation of Samples for Comparison
Emulsion 7-a: An aqueous potassium bromide solution and an aqueous
silver nitrate solution were added simultaneously over a 20-minute
period to an aqueous gelatin solution kept at 35.degree. C. During
the addition, the pAg was kept at 7.5. Thus, a cubic fine grain
monodisperse emulsion having an average grain size of 0.06 .mu.m
was prepared. This emulsion was desalted using the flocculation
process, and gelatin and the stabilizer (II-1) were added thereto
in succession.
Emulsion 7-b: An emulsion was prepared in the same manner as
emulsion 7-a, except the addition time of the aqueous potassium
bromide and silver nitrate solutions was changed to 10 minutes
(grain size: 0.055 .mu.m).
Three kinds of superfine grains were prepared in the same manner as
the silver bromide superfine grain invention emulsions, 1-G and 1-H
and the superfine grain comparison emulsion 1-A (prepared in
Example 1), respectively. These emulsions were desalted and admixed
with gelatin and the stabilizer (II-1) in succession. Thus, the
emulsions 7-C, 7-d and 7-e were prepared.
A merocyanine dye V-12 was added to each of the thus prepared
emulsions 7-a, 7-b (comparison), 7-c, 7-d (invention) and 7-e
(comparison), in the amount determined as optimum for spectral
sensitization. The resulting emulsion was coated on a glass plate
so as to have a silver coverage of 3 g/m.sup.2 and a gelatin
coverage of 2 g/m.sup.2. Thus, samples (7-1) to (7-5) were
obtained.
These samples were scanned with Ar-laser beam having a wavelength
of 488 nm. The scanning exposure was performed twice for each
sample by controlling the diameter of the beam to be 2 .mu.m and 5
.mu.m, respectively, on the sample surface. Then, the samples were
subjected to the following reversal processing.
______________________________________ Processing Steps:
Development (a) 20.degree. C. 5 minutes Bleaching 20.degree. C. 5
minute Washing 20.degree. C. 1 minutes Stabilization 20.degree. C.
5 minutes Washing 20.degree. C. 1 minutes Overall uniform exposure
Development (b) 20.degree. C. 6 minutes Washing 20.degree. C. 10
minutes Air drying Formula of Developer (a): Metol 4.0 g
Hydroquinone 2.0 g Sodium carbonate 40.0 g KBr 2.0 g Sodium sulfite
40.0 g Potassium thiocyanate 5.0 g H.sub.2 O to make 1.0 l Formula
of Bleaching Solution: Potassium dichromate 5.0 g Conc. sulfuric
acid 10 ml (specific gravity: 1.85) H.sub.2 O to make 1.0 l Formula
of Stabilizing Bath: Sodium sulfite 100.0 g H.sub.2 O to make 1.0 l
Formula of Developer (b): Metol 1.0 g Hydroquinone 5.0 g Sodium
carbonate 30.0 g KBr 0.5 g Sodium sulfite 40.0 g H.sub.2 O to make
1.0 l ______________________________________
The thus processed samples were observed with a high resolution,
field-emission type scanning electron microscope (Hitachi S-900),
and the width of the lines recorded on each sample was measured.
The results obtained are shown in Table 7-1.
TABLE 7-1 ______________________________________ Line Width
Reproducibility Emulsion Grain Size 2 .mu.m 5 .mu.m Sample Used
(.mu.m) (.mu.m) (.mu.m) Note ______________________________________
7-1 7-a 0.06 2.7 5.7 Comparison 7-2 7-b 0.055 2.7 5.7 " 7-3 7-c
0.02 2.0 5.0 Invention 7-4 7-d 0.015 2.0 5.0 " 7-5 7-e 0.06 2.5 5.5
Comparison ______________________________________
As can be seen from Table 7-1, an increase in line width was
observed in each of the comparison samples (7-1), (7-2) and (7-5),
whereas no increase in line width was observed in each of the
invention sample (7-3) and (7-4); that is, high density recording
was carried out faithfully with the present invention. These
results demonstrate that the silver halide photographic material of
this invention can provide a method of recording images of high
density with scanning exposure.
While the invention has been described in detail and with reference
to specific embodiments thereof, it will be apparent to one skilled
in the art that various changes and modifications can be made
therein without departing from the spirit and scope thereof.
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